vendorify
diff --git a/go/vendor/github.com/globalsign/mgo/bson/LICENSE b/go/vendor/github.com/globalsign/mgo/bson/LICENSE
new file mode 100644
index 0000000..8903260
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/LICENSE
@@ -0,0 +1,25 @@
+BSON library for Go
+
+Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met: 
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer. 
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution. 
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/go/vendor/github.com/globalsign/mgo/bson/README.md b/go/vendor/github.com/globalsign/mgo/bson/README.md
new file mode 100644
index 0000000..5c5819e
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/README.md
@@ -0,0 +1,12 @@
+[![GoDoc](https://godoc.org/github.com/globalsign/mgo/bson?status.svg)](https://godoc.org/github.com/globalsign/mgo/bson)
+
+An Implementation of BSON for Go
+--------------------------------
+
+Package bson is an implementation of the [BSON specification](http://bsonspec.org) for Go.
+
+While the BSON package implements the BSON spec as faithfully as possible, there
+is some MongoDB specific behaviour (such as map keys `$in`, `$all`, etc) in the
+`bson` package. The priority is for backwards compatibility for the `mgo`
+driver, though fixes for obviously buggy behaviour is welcome (and features, etc
+behind feature flags).
diff --git a/go/vendor/github.com/globalsign/mgo/bson/bson.go b/go/vendor/github.com/globalsign/mgo/bson/bson.go
new file mode 100644
index 0000000..eb87ef6
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/bson.go
@@ -0,0 +1,836 @@
+// BSON library for Go
+//
+// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Package bson is an implementation of the BSON specification for Go:
+//
+//     http://bsonspec.org
+//
+// It was created as part of the mgo MongoDB driver for Go, but is standalone
+// and may be used on its own without the driver.
+package bson
+
+import (
+	"bytes"
+	"crypto/md5"
+	"crypto/rand"
+	"encoding/binary"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"os"
+	"reflect"
+	"runtime"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+//go:generate go run bson_corpus_spec_test_generator.go
+
+// --------------------------------------------------------------------------
+// The public API.
+
+// Element types constants from BSON specification.
+const (
+	ElementFloat64                byte = 0x01
+	ElementString                 byte = 0x02
+	ElementDocument               byte = 0x03
+	ElementArray                  byte = 0x04
+	ElementBinary                 byte = 0x05
+	Element06                     byte = 0x06
+	ElementObjectId               byte = 0x07
+	ElementBool                   byte = 0x08
+	ElementDatetime               byte = 0x09
+	ElementNil                    byte = 0x0A
+	ElementRegEx                  byte = 0x0B
+	ElementDBPointer              byte = 0x0C
+	ElementJavaScriptWithoutScope byte = 0x0D
+	ElementSymbol                 byte = 0x0E
+	ElementJavaScriptWithScope    byte = 0x0F
+	ElementInt32                  byte = 0x10
+	ElementTimestamp              byte = 0x11
+	ElementInt64                  byte = 0x12
+	ElementDecimal128             byte = 0x13
+	ElementMinKey                 byte = 0xFF
+	ElementMaxKey                 byte = 0x7F
+
+	BinaryGeneric     byte = 0x00
+	BinaryFunction    byte = 0x01
+	BinaryBinaryOld   byte = 0x02
+	BinaryUUIDOld     byte = 0x03
+	BinaryUUID        byte = 0x04
+	BinaryMD5         byte = 0x05
+	BinaryUserDefined byte = 0x80
+)
+
+// Getter interface: a value implementing the bson.Getter interface will have its GetBSON
+// method called when the given value has to be marshalled, and the result
+// of this method will be marshaled in place of the actual object.
+//
+// If GetBSON returns return a non-nil error, the marshalling procedure
+// will stop and error out with the provided value.
+type Getter interface {
+	GetBSON() (interface{}, error)
+}
+
+// Setter interface: a value implementing the bson.Setter interface will receive the BSON
+// value via the SetBSON method during unmarshaling, and the object
+// itself will not be changed as usual.
+//
+// If setting the value works, the method should return nil or alternatively
+// bson.ErrSetZero to set the respective field to its zero value (nil for
+// pointer types). If SetBSON returns a value of type bson.TypeError, the
+// BSON value will be omitted from a map or slice being decoded and the
+// unmarshalling will continue. If it returns any other non-nil error, the
+// unmarshalling procedure will stop and error out with the provided value.
+//
+// This interface is generally useful in pointer receivers, since the method
+// will want to change the receiver. A type field that implements the Setter
+// interface doesn't have to be a pointer, though.
+//
+// Unlike the usual behavior, unmarshalling onto a value that implements a
+// Setter interface will NOT reset the value to its zero state. This allows
+// the value to decide by itself how to be unmarshalled.
+//
+// For example:
+//
+//     type MyString string
+//
+//     func (s *MyString) SetBSON(raw bson.Raw) error {
+//         return raw.Unmarshal(s)
+//     }
+//
+type Setter interface {
+	SetBSON(raw Raw) error
+}
+
+// ErrSetZero may be returned from a SetBSON method to have the value set to
+// its respective zero value. When used in pointer values, this will set the
+// field to nil rather than to the pre-allocated value.
+var ErrSetZero = errors.New("set to zero")
+
+// M is a convenient alias for a map[string]interface{} map, useful for
+// dealing with BSON in a native way.  For instance:
+//
+//     bson.M{"a": 1, "b": true}
+//
+// There's no special handling for this type in addition to what's done anyway
+// for an equivalent map type.  Elements in the map will be dumped in an
+// undefined ordered. See also the bson.D type for an ordered alternative.
+type M map[string]interface{}
+
+// D represents a BSON document containing ordered elements. For example:
+//
+//     bson.D{{"a", 1}, {"b", true}}
+//
+// In some situations, such as when creating indexes for MongoDB, the order in
+// which the elements are defined is important.  If the order is not important,
+// using a map is generally more comfortable. See bson.M and bson.RawD.
+type D []DocElem
+
+// DocElem is an element of the bson.D document representation.
+type DocElem struct {
+	Name  string
+	Value interface{}
+}
+
+// Map returns a map out of the ordered element name/value pairs in d.
+func (d D) Map() (m M) {
+	m = make(M, len(d))
+	for _, item := range d {
+		m[item.Name] = item.Value
+	}
+	return m
+}
+
+// The Raw type represents raw unprocessed BSON documents and elements.
+// Kind is the kind of element as defined per the BSON specification, and
+// Data is the raw unprocessed data for the respective element.
+// Using this type it is possible to unmarshal or marshal values partially.
+//
+// Relevant documentation:
+//
+//     http://bsonspec.org/#/specification
+//
+type Raw struct {
+	Kind byte
+	Data []byte
+}
+
+// RawD represents a BSON document containing raw unprocessed elements.
+// This low-level representation may be useful when lazily processing
+// documents of uncertain content, or when manipulating the raw content
+// documents in general.
+type RawD []RawDocElem
+
+// RawDocElem elements of RawD type.
+type RawDocElem struct {
+	Name  string
+	Value Raw
+}
+
+// ObjectId is a unique ID identifying a BSON value. It must be exactly 12 bytes
+// long. MongoDB objects by default have such a property set in their "_id"
+// property.
+//
+// http://www.mongodb.org/display/DOCS/Object+Ids
+type ObjectId string
+
+// ObjectIdHex returns an ObjectId from the provided hex representation.
+// Calling this function with an invalid hex representation will
+// cause a runtime panic. See the IsObjectIdHex function.
+func ObjectIdHex(s string) ObjectId {
+	d, err := hex.DecodeString(s)
+	if err != nil || len(d) != 12 {
+		panic(fmt.Sprintf("invalid input to ObjectIdHex: %q", s))
+	}
+	return ObjectId(d)
+}
+
+// IsObjectIdHex returns whether s is a valid hex representation of
+// an ObjectId. See the ObjectIdHex function.
+func IsObjectIdHex(s string) bool {
+	if len(s) != 24 {
+		return false
+	}
+	_, err := hex.DecodeString(s)
+	return err == nil
+}
+
+// objectIdCounter is atomically incremented when generating a new ObjectId
+// using NewObjectId() function. It's used as a counter part of an id.
+var objectIdCounter = readRandomUint32()
+
+// readRandomUint32 returns a random objectIdCounter.
+func readRandomUint32() uint32 {
+	var b [4]byte
+	_, err := io.ReadFull(rand.Reader, b[:])
+	if err != nil {
+		panic(fmt.Errorf("cannot read random object id: %v", err))
+	}
+	return uint32((uint32(b[0]) << 0) | (uint32(b[1]) << 8) | (uint32(b[2]) << 16) | (uint32(b[3]) << 24))
+}
+
+// machineId stores machine id generated once and used in subsequent calls
+// to NewObjectId function.
+var machineId = readMachineId()
+var processId = os.Getpid()
+
+// readMachineId generates and returns a machine id.
+// If this function fails to get the hostname it will cause a runtime error.
+func readMachineId() []byte {
+	var sum [3]byte
+	id := sum[:]
+	hostname, err1 := os.Hostname()
+	if err1 != nil {
+		_, err2 := io.ReadFull(rand.Reader, id)
+		if err2 != nil {
+			panic(fmt.Errorf("cannot get hostname: %v; %v", err1, err2))
+		}
+		return id
+	}
+	hw := md5.New()
+	hw.Write([]byte(hostname))
+	copy(id, hw.Sum(nil))
+	return id
+}
+
+// NewObjectId returns a new unique ObjectId.
+func NewObjectId() ObjectId {
+	var b [12]byte
+	// Timestamp, 4 bytes, big endian
+	binary.BigEndian.PutUint32(b[:], uint32(time.Now().Unix()))
+	// Machine, first 3 bytes of md5(hostname)
+	b[4] = machineId[0]
+	b[5] = machineId[1]
+	b[6] = machineId[2]
+	// Pid, 2 bytes, specs don't specify endianness, but we use big endian.
+	b[7] = byte(processId >> 8)
+	b[8] = byte(processId)
+	// Increment, 3 bytes, big endian
+	i := atomic.AddUint32(&objectIdCounter, 1)
+	b[9] = byte(i >> 16)
+	b[10] = byte(i >> 8)
+	b[11] = byte(i)
+	return ObjectId(b[:])
+}
+
+// NewObjectIdWithTime returns a dummy ObjectId with the timestamp part filled
+// with the provided number of seconds from epoch UTC, and all other parts
+// filled with zeroes. It's not safe to insert a document with an id generated
+// by this method, it is useful only for queries to find documents with ids
+// generated before or after the specified timestamp.
+func NewObjectIdWithTime(t time.Time) ObjectId {
+	var b [12]byte
+	binary.BigEndian.PutUint32(b[:4], uint32(t.Unix()))
+	return ObjectId(string(b[:]))
+}
+
+// String returns a hex string representation of the id.
+// Example: ObjectIdHex("4d88e15b60f486e428412dc9").
+func (id ObjectId) String() string {
+	return fmt.Sprintf(`ObjectIdHex("%x")`, string(id))
+}
+
+// Hex returns a hex representation of the ObjectId.
+func (id ObjectId) Hex() string {
+	return hex.EncodeToString([]byte(id))
+}
+
+// MarshalJSON turns a bson.ObjectId into a json.Marshaller.
+func (id ObjectId) MarshalJSON() ([]byte, error) {
+	return []byte(fmt.Sprintf(`"%x"`, string(id))), nil
+}
+
+var nullBytes = []byte("null")
+
+// UnmarshalJSON turns *bson.ObjectId into a json.Unmarshaller.
+func (id *ObjectId) UnmarshalJSON(data []byte) error {
+	if len(data) > 0 && (data[0] == '{' || data[0] == 'O') {
+		var v struct {
+			Id   json.RawMessage `json:"$oid"`
+			Func struct {
+				Id json.RawMessage
+			} `json:"$oidFunc"`
+		}
+		err := jdec(data, &v)
+		if err == nil {
+			if len(v.Id) > 0 {
+				data = []byte(v.Id)
+			} else {
+				data = []byte(v.Func.Id)
+			}
+		}
+	}
+	if len(data) == 2 && data[0] == '"' && data[1] == '"' || bytes.Equal(data, nullBytes) {
+		*id = ""
+		return nil
+	}
+	if len(data) != 26 || data[0] != '"' || data[25] != '"' {
+		return fmt.Errorf("invalid ObjectId in JSON: %s", string(data))
+	}
+	var buf [12]byte
+	_, err := hex.Decode(buf[:], data[1:25])
+	if err != nil {
+		return fmt.Errorf("invalid ObjectId in JSON: %s (%s)", string(data), err)
+	}
+	*id = ObjectId(string(buf[:]))
+	return nil
+}
+
+// MarshalText turns bson.ObjectId into an encoding.TextMarshaler.
+func (id ObjectId) MarshalText() ([]byte, error) {
+	return []byte(fmt.Sprintf("%x", string(id))), nil
+}
+
+// UnmarshalText turns *bson.ObjectId into an encoding.TextUnmarshaler.
+func (id *ObjectId) UnmarshalText(data []byte) error {
+	if len(data) == 1 && data[0] == ' ' || len(data) == 0 {
+		*id = ""
+		return nil
+	}
+	if len(data) != 24 {
+		return fmt.Errorf("invalid ObjectId: %s", data)
+	}
+	var buf [12]byte
+	_, err := hex.Decode(buf[:], data[:])
+	if err != nil {
+		return fmt.Errorf("invalid ObjectId: %s (%s)", data, err)
+	}
+	*id = ObjectId(string(buf[:]))
+	return nil
+}
+
+// Valid returns true if id is valid. A valid id must contain exactly 12 bytes.
+func (id ObjectId) Valid() bool {
+	return len(id) == 12
+}
+
+// byteSlice returns byte slice of id from start to end.
+// Calling this function with an invalid id will cause a runtime panic.
+func (id ObjectId) byteSlice(start, end int) []byte {
+	if len(id) != 12 {
+		panic(fmt.Sprintf("invalid ObjectId: %q", string(id)))
+	}
+	return []byte(string(id)[start:end])
+}
+
+// Time returns the timestamp part of the id.
+// It's a runtime error to call this method with an invalid id.
+func (id ObjectId) Time() time.Time {
+	// First 4 bytes of ObjectId is 32-bit big-endian seconds from epoch.
+	secs := int64(binary.BigEndian.Uint32(id.byteSlice(0, 4)))
+	return time.Unix(secs, 0)
+}
+
+// Machine returns the 3-byte machine id part of the id.
+// It's a runtime error to call this method with an invalid id.
+func (id ObjectId) Machine() []byte {
+	return id.byteSlice(4, 7)
+}
+
+// Pid returns the process id part of the id.
+// It's a runtime error to call this method with an invalid id.
+func (id ObjectId) Pid() uint16 {
+	return binary.BigEndian.Uint16(id.byteSlice(7, 9))
+}
+
+// Counter returns the incrementing value part of the id.
+// It's a runtime error to call this method with an invalid id.
+func (id ObjectId) Counter() int32 {
+	b := id.byteSlice(9, 12)
+	// Counter is stored as big-endian 3-byte value
+	return int32(uint32(b[0])<<16 | uint32(b[1])<<8 | uint32(b[2]))
+}
+
+// The Symbol type is similar to a string and is used in languages with a
+// distinct symbol type.
+type Symbol string
+
+// Now returns the current time with millisecond precision. MongoDB stores
+// timestamps with the same precision, so a Time returned from this method
+// will not change after a roundtrip to the database. That's the only reason
+// why this function exists. Using the time.Now function also works fine
+// otherwise.
+func Now() time.Time {
+	return time.Unix(0, time.Now().UnixNano()/1e6*1e6)
+}
+
+// MongoTimestamp is a special internal type used by MongoDB that for some
+// strange reason has its own datatype defined in BSON.
+type MongoTimestamp int64
+
+// Time returns the time part of ts which is stored with second precision.
+func (ts MongoTimestamp) Time() time.Time {
+	return time.Unix(int64(uint64(ts)>>32), 0)
+}
+
+// Counter returns the counter part of ts.
+func (ts MongoTimestamp) Counter() uint32 {
+	return uint32(ts)
+}
+
+// NewMongoTimestamp creates a timestamp using the given
+// date `t` (with second precision) and counter `c` (unique for `t`).
+//
+// Returns an error if time `t` is not between 1970-01-01T00:00:00Z
+// and 2106-02-07T06:28:15Z (inclusive).
+//
+// Note that two MongoTimestamps should never have the same (time, counter) combination:
+// the caller must ensure the counter `c` is increased if creating multiple MongoTimestamp
+// values for the same time `t` (ignoring fractions of seconds).
+func NewMongoTimestamp(t time.Time, c uint32) (MongoTimestamp, error) {
+	u := t.Unix()
+	if u < 0 || u > math.MaxUint32 {
+		return -1, errors.New("invalid value for time")
+	}
+
+	i := int64(u<<32 | int64(c))
+
+	return MongoTimestamp(i), nil
+}
+
+type orderKey int64
+
+// MaxKey is a special value that compares higher than all other possible BSON
+// values in a MongoDB database.
+var MaxKey = orderKey(1<<63 - 1)
+
+// MinKey is a special value that compares lower than all other possible BSON
+// values in a MongoDB database.
+var MinKey = orderKey(-1 << 63)
+
+type undefined struct{}
+
+// Undefined represents the undefined BSON value.
+var Undefined undefined
+
+// Binary is a representation for non-standard binary values.  Any kind should
+// work, but the following are known as of this writing:
+//
+//   0x00 - Generic. This is decoded as []byte(data), not Binary{0x00, data}.
+//   0x01 - Function (!?)
+//   0x02 - Obsolete generic.
+//   0x03 - UUID
+//   0x05 - MD5
+//   0x80 - User defined.
+//
+type Binary struct {
+	Kind byte
+	Data []byte
+}
+
+// RegEx represents a regular expression.  The Options field may contain
+// individual characters defining the way in which the pattern should be
+// applied, and must be sorted. Valid options as of this writing are 'i' for
+// case insensitive matching, 'm' for multi-line matching, 'x' for verbose
+// mode, 'l' to make \w, \W, and similar be locale-dependent, 's' for dot-all
+// mode (a '.' matches everything), and 'u' to make \w, \W, and similar match
+// unicode. The value of the Options parameter is not verified before being
+// marshaled into the BSON format.
+type RegEx struct {
+	Pattern string
+	Options string
+}
+
+// JavaScript is a type that holds JavaScript code. If Scope is non-nil, it
+// will be marshaled as a mapping from identifiers to values that may be
+// used when evaluating the provided Code.
+type JavaScript struct {
+	Code  string
+	Scope interface{}
+}
+
+// DBPointer refers to a document id in a namespace.
+//
+// This type is deprecated in the BSON specification and should not be used
+// except for backwards compatibility with ancient applications.
+type DBPointer struct {
+	Namespace string
+	Id        ObjectId
+}
+
+const initialBufferSize = 64
+
+func handleErr(err *error) {
+	if r := recover(); r != nil {
+		if _, ok := r.(runtime.Error); ok {
+			panic(r)
+		} else if _, ok := r.(externalPanic); ok {
+			panic(r)
+		} else if s, ok := r.(string); ok {
+			*err = errors.New(s)
+		} else if e, ok := r.(error); ok {
+			*err = e
+		} else {
+			panic(r)
+		}
+	}
+}
+
+// Marshal serializes the in value, which may be a map or a struct value.
+// In the case of struct values, only exported fields will be serialized,
+// and the order of serialized fields will match that of the struct itself.
+// The lowercased field name is used as the key for each exported field,
+// but this behavior may be changed using the respective field tag.
+// The tag may also contain flags to tweak the marshalling behavior for
+// the field. The tag formats accepted are:
+//
+//     "[<key>][,<flag1>[,<flag2>]]"
+//
+//     `(...) bson:"[<key>][,<flag1>[,<flag2>]]" (...)`
+//
+// The following flags are currently supported:
+//
+//     omitempty  Only include the field if it's not set to the zero
+//                value for the type or to empty slices or maps.
+//
+//     minsize    Marshal an int64 value as an int32, if that's feasible
+//                while preserving the numeric value.
+//
+//     inline     Inline the field, which must be a struct or a map,
+//                causing all of its fields or keys to be processed as if
+//                they were part of the outer struct. For maps, keys must
+//                not conflict with the bson keys of other struct fields.
+//
+// Some examples:
+//
+//     type T struct {
+//         A bool
+//         B int    "myb"
+//         C string "myc,omitempty"
+//         D string `bson:",omitempty" json:"jsonkey"`
+//         E int64  ",minsize"
+//         F int64  "myf,omitempty,minsize"
+//     }
+//
+func Marshal(in interface{}) (out []byte, err error) {
+	return MarshalBuffer(in, make([]byte, 0, initialBufferSize))
+}
+
+// MarshalBuffer behaves the same way as Marshal, except that instead of
+// allocating a new byte slice it tries to use the received byte slice and
+// only allocates more memory if necessary to fit the marshaled value.
+func MarshalBuffer(in interface{}, buf []byte) (out []byte, err error) {
+	defer handleErr(&err)
+	e := &encoder{buf}
+	e.addDoc(reflect.ValueOf(in))
+	return e.out, nil
+}
+
+// Unmarshal deserializes data from in into the out value.  The out value
+// must be a map, a pointer to a struct, or a pointer to a bson.D value.
+// In the case of struct values, only exported fields will be deserialized.
+// The lowercased field name is used as the key for each exported field,
+// but this behavior may be changed using the respective field tag.
+// The tag may also contain flags to tweak the marshalling behavior for
+// the field. The tag formats accepted are:
+//
+//     "[<key>][,<flag1>[,<flag2>]]"
+//
+//     `(...) bson:"[<key>][,<flag1>[,<flag2>]]" (...)`
+//
+// The following flags are currently supported during unmarshal (see the
+// Marshal method for other flags):
+//
+//     inline     Inline the field, which must be a struct or a map.
+//                Inlined structs are handled as if its fields were part
+//                of the outer struct. An inlined map causes keys that do
+//                not match any other struct field to be inserted in the
+//                map rather than being discarded as usual.
+//
+// The target field or element types of out may not necessarily match
+// the BSON values of the provided data.  The following conversions are
+// made automatically:
+//
+// - Numeric types are converted if at least the integer part of the
+//   value would be preserved correctly
+// - Bools are converted to numeric types as 1 or 0
+// - Numeric types are converted to bools as true if not 0 or false otherwise
+// - Binary and string BSON data is converted to a string, array or byte slice
+//
+// If the value would not fit the type and cannot be converted, it's
+// silently skipped.
+//
+// Pointer values are initialized when necessary.
+func Unmarshal(in []byte, out interface{}) (err error) {
+	if raw, ok := out.(*Raw); ok {
+		raw.Kind = 3
+		raw.Data = in
+		return nil
+	}
+	defer handleErr(&err)
+	v := reflect.ValueOf(out)
+	switch v.Kind() {
+	case reflect.Ptr:
+		fallthrough
+	case reflect.Map:
+		d := newDecoder(in)
+		d.readDocTo(v)
+		if d.i < len(d.in) {
+			return errors.New("document is corrupted")
+		}
+	case reflect.Struct:
+		return errors.New("unmarshal can't deal with struct values. Use a pointer")
+	default:
+		return errors.New("unmarshal needs a map or a pointer to a struct")
+	}
+	return nil
+}
+
+// Unmarshal deserializes raw into the out value.  If the out value type
+// is not compatible with raw, a *bson.TypeError is returned.
+//
+// See the Unmarshal function documentation for more details on the
+// unmarshalling process.
+func (raw Raw) Unmarshal(out interface{}) (err error) {
+	defer handleErr(&err)
+	v := reflect.ValueOf(out)
+	switch v.Kind() {
+	case reflect.Ptr:
+		v = v.Elem()
+		fallthrough
+	case reflect.Map:
+		d := newDecoder(raw.Data)
+		good := d.readElemTo(v, raw.Kind)
+		if !good {
+			return &TypeError{v.Type(), raw.Kind}
+		}
+	case reflect.Struct:
+		return errors.New("raw Unmarshal can't deal with struct values. Use a pointer")
+	default:
+		return errors.New("raw Unmarshal needs a map or a valid pointer")
+	}
+	return nil
+}
+
+// TypeError store details for type error occuring
+// during unmarshaling
+type TypeError struct {
+	Type reflect.Type
+	Kind byte
+}
+
+func (e *TypeError) Error() string {
+	return fmt.Sprintf("BSON kind 0x%02x isn't compatible with type %s", e.Kind, e.Type.String())
+}
+
+// --------------------------------------------------------------------------
+// Maintain a mapping of keys to structure field indexes
+
+type structInfo struct {
+	FieldsMap  map[string]fieldInfo
+	FieldsList []fieldInfo
+	InlineMap  int
+	Zero       reflect.Value
+}
+
+type fieldInfo struct {
+	Key       string
+	Num       int
+	OmitEmpty bool
+	MinSize   bool
+	Inline    []int
+}
+
+var structMap = make(map[reflect.Type]*structInfo)
+var structMapMutex sync.RWMutex
+
+type externalPanic string
+
+func (e externalPanic) String() string {
+	return string(e)
+}
+
+func getStructInfo(st reflect.Type) (*structInfo, error) {
+	structMapMutex.RLock()
+	sinfo, found := structMap[st]
+	structMapMutex.RUnlock()
+	if found {
+		return sinfo, nil
+	}
+	n := st.NumField()
+	fieldsMap := make(map[string]fieldInfo)
+	fieldsList := make([]fieldInfo, 0, n)
+	inlineMap := -1
+	for i := 0; i != n; i++ {
+		field := st.Field(i)
+		if field.PkgPath != "" && !field.Anonymous {
+			continue // Private field
+		}
+
+		info := fieldInfo{Num: i}
+
+		tag := field.Tag.Get("bson")
+
+		// Fall-back to JSON struct tag, if feature flag is set.
+		if tag == "" && useJSONTagFallback {
+			tag = field.Tag.Get("json")
+		}
+
+		// If there's no bson/json tag available.
+		if tag == "" {
+			// If there's no tag, and also no tag: value splits (i.e. no colon)
+			// then assume the entire tag is the value
+			if strings.Index(string(field.Tag), ":") < 0 {
+				tag = string(field.Tag)
+			}
+		}
+
+		if tag == "-" {
+			continue
+		}
+
+		inline := false
+		fields := strings.Split(tag, ",")
+		if len(fields) > 1 {
+			for _, flag := range fields[1:] {
+				switch flag {
+				case "omitempty":
+					info.OmitEmpty = true
+				case "minsize":
+					info.MinSize = true
+				case "inline":
+					inline = true
+				default:
+					msg := fmt.Sprintf("Unsupported flag %q in tag %q of type %s", flag, tag, st)
+					panic(externalPanic(msg))
+				}
+			}
+			tag = fields[0]
+		}
+
+		if inline {
+			switch field.Type.Kind() {
+			case reflect.Map:
+				if inlineMap >= 0 {
+					return nil, errors.New("Multiple ,inline maps in struct " + st.String())
+				}
+				if field.Type.Key() != reflect.TypeOf("") {
+					return nil, errors.New("Option ,inline needs a map with string keys in struct " + st.String())
+				}
+				inlineMap = info.Num
+			case reflect.Ptr:
+				// allow only pointer to struct
+				if kind := field.Type.Elem().Kind(); kind != reflect.Struct {
+					return nil, errors.New("Option ,inline allows a pointer only to a struct, was given pointer to " + kind.String())
+				}
+
+				field.Type = field.Type.Elem()
+				fallthrough
+			case reflect.Struct:
+				sinfo, err := getStructInfo(field.Type)
+				if err != nil {
+					return nil, err
+				}
+				for _, finfo := range sinfo.FieldsList {
+					if _, found := fieldsMap[finfo.Key]; found {
+						msg := "Duplicated key '" + finfo.Key + "' in struct " + st.String()
+						return nil, errors.New(msg)
+					}
+					if finfo.Inline == nil {
+						finfo.Inline = []int{i, finfo.Num}
+					} else {
+						finfo.Inline = append([]int{i}, finfo.Inline...)
+					}
+					fieldsMap[finfo.Key] = finfo
+					fieldsList = append(fieldsList, finfo)
+				}
+			default:
+				panic("Option ,inline needs a struct value or a pointer to a struct or map field")
+			}
+			continue
+		}
+
+		if tag != "" {
+			info.Key = tag
+		} else {
+			info.Key = strings.ToLower(field.Name)
+		}
+
+		if _, found = fieldsMap[info.Key]; found {
+			msg := "Duplicated key '" + info.Key + "' in struct " + st.String()
+			return nil, errors.New(msg)
+		}
+
+		fieldsList = append(fieldsList, info)
+		fieldsMap[info.Key] = info
+	}
+	sinfo = &structInfo{
+		fieldsMap,
+		fieldsList,
+		inlineMap,
+		reflect.New(st).Elem(),
+	}
+	structMapMutex.Lock()
+	structMap[st] = sinfo
+	structMapMutex.Unlock()
+	return sinfo, nil
+}
diff --git a/go/vendor/github.com/globalsign/mgo/bson/bson_corpus_spec_test_generator.go b/go/vendor/github.com/globalsign/mgo/bson/bson_corpus_spec_test_generator.go
new file mode 100644
index 0000000..3525a00
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/bson_corpus_spec_test_generator.go
@@ -0,0 +1,294 @@
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/format"
+	"html/template"
+	"io/ioutil"
+	"log"
+	"path/filepath"
+	"strings"
+
+	"github.com/globalsign/mgo/internal/json"
+)
+
+func main() {
+	log.SetFlags(0)
+	log.SetPrefix(name + ": ")
+
+	var g Generator
+
+	fmt.Fprintf(&g, "// Code generated by \"%s.go\"; DO NOT EDIT\n\n", name)
+
+	src := g.generate()
+
+	err := ioutil.WriteFile(fmt.Sprintf("%s.go", strings.TrimSuffix(name, "_generator")), src, 0644)
+	if err != nil {
+		log.Fatalf("writing output: %s", err)
+	}
+}
+
+// Generator holds the state of the analysis. Primarily used to buffer
+// the output for format.Source.
+type Generator struct {
+	bytes.Buffer // Accumulated output.
+}
+
+// format returns the gofmt-ed contents of the Generator's buffer.
+func (g *Generator) format() []byte {
+	src, err := format.Source(g.Bytes())
+	if err != nil {
+		// Should never happen, but can arise when developing this code.
+		// The user can compile the output to see the error.
+		log.Printf("warning: internal error: invalid Go generated: %s", err)
+		log.Printf("warning: compile the package to analyze the error")
+		return g.Bytes()
+	}
+	return src
+}
+
+// EVERYTHING ABOVE IS CONSTANT BETWEEN THE GENERATORS
+
+const name = "bson_corpus_spec_test_generator"
+
+func (g *Generator) generate() []byte {
+
+	testFiles, err := filepath.Glob("./specdata/specifications/source/bson-corpus/tests/*.json")
+	if err != nil {
+		log.Fatalf("error reading bson-corpus files: %s", err)
+	}
+
+	tests, err := g.loadTests(testFiles)
+	if err != nil {
+		log.Fatalf("error loading tests: %s", err)
+	}
+
+	tmpl, err := g.getTemplate()
+	if err != nil {
+		log.Fatalf("error loading template: %s", err)
+	}
+
+	tmpl.Execute(&g.Buffer, tests)
+
+	return g.format()
+}
+
+func (g *Generator) loadTests(filenames []string) ([]*testDef, error) {
+	var tests []*testDef
+	for _, filename := range filenames {
+		test, err := g.loadTest(filename)
+		if err != nil {
+			return nil, err
+		}
+
+		tests = append(tests, test)
+	}
+
+	return tests, nil
+}
+
+func (g *Generator) loadTest(filename string) (*testDef, error) {
+	content, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	var testDef testDef
+	err = json.Unmarshal(content, &testDef)
+	if err != nil {
+		return nil, err
+	}
+
+	names := make(map[string]struct{})
+
+	for i := len(testDef.Valid) - 1; i >= 0; i-- {
+		if testDef.BsonType == "0x05" && testDef.Valid[i].Description == "subtype 0x02" {
+			testDef.Valid = append(testDef.Valid[:i], testDef.Valid[i+1:]...)
+			continue
+		}
+
+		name := cleanupFuncName(testDef.Description + "_" + testDef.Valid[i].Description)
+		nameIdx := name
+		j := 1
+		for {
+			if _, ok := names[nameIdx]; !ok {
+				break
+			}
+
+			nameIdx = fmt.Sprintf("%s_%d", name, j)
+		}
+
+		names[nameIdx] = struct{}{}
+
+		testDef.Valid[i].TestDef = &testDef
+		testDef.Valid[i].Name = nameIdx
+		testDef.Valid[i].StructTest = testDef.TestKey != "" &&
+			(testDef.BsonType != "0x05" || strings.Contains(testDef.Valid[i].Description, "0x00")) &&
+			!testDef.Deprecated
+	}
+
+	for i := len(testDef.DecodeErrors) - 1; i >= 0; i-- {
+		if strings.Contains(testDef.DecodeErrors[i].Description, "UTF-8") {
+			testDef.DecodeErrors = append(testDef.DecodeErrors[:i], testDef.DecodeErrors[i+1:]...)
+			continue
+		}
+
+		name := cleanupFuncName(testDef.Description + "_" + testDef.DecodeErrors[i].Description)
+		nameIdx := name
+		j := 1
+		for {
+			if _, ok := names[nameIdx]; !ok {
+				break
+			}
+
+			nameIdx = fmt.Sprintf("%s_%d", name, j)
+		}
+		names[nameIdx] = struct{}{}
+
+		testDef.DecodeErrors[i].Name = nameIdx
+	}
+
+	return &testDef, nil
+}
+
+func (g *Generator) getTemplate() (*template.Template, error) {
+	content := `package bson_test
+
+import (
+    "encoding/hex"
+	"time"
+
+	. "gopkg.in/check.v1"
+    "github.com/globalsign/mgo/bson"
+)
+
+func testValid(c *C, in []byte, expected []byte, result interface{}) {
+	err := bson.Unmarshal(in, result)
+	c.Assert(err, IsNil)
+
+	out, err := bson.Marshal(result)
+	c.Assert(err, IsNil)
+
+	c.Assert(string(expected), Equals, string(out), Commentf("roundtrip failed for %T, expected '%x' but got '%x'", result, expected, out))
+}
+
+func testDecodeSkip(c *C, in []byte) {
+	err := bson.Unmarshal(in, &struct{}{})
+	c.Assert(err, IsNil)
+}
+
+func testDecodeError(c *C, in []byte, result interface{}) {
+	err := bson.Unmarshal(in, result)
+	c.Assert(err, Not(IsNil))
+}
+
+{{range .}}
+{{range .Valid}}
+func (s *S) Test{{.Name}}(c *C) {
+    b, err := hex.DecodeString("{{.Bson}}")
+	c.Assert(err, IsNil)
+
+    {{if .CanonicalBson}}
+    cb, err := hex.DecodeString("{{.CanonicalBson}}")
+	c.Assert(err, IsNil)
+	{{else}}
+    cb := b
+    {{end}}
+
+    var resultD bson.D
+	testValid(c, b, cb, &resultD)
+	{{if .StructTest}}var resultS struct {
+		Element {{.TestDef.GoType}} ` + "`bson:\"{{.TestDef.TestKey}}\"`" + `
+	}
+	testValid(c, b, cb, &resultS){{end}}
+
+	testDecodeSkip(c, b)
+}
+{{end}}
+
+{{range .DecodeErrors}}
+func (s *S) Test{{.Name}}(c *C) {
+	b, err := hex.DecodeString("{{.Bson}}")
+	c.Assert(err, IsNil)
+
+	var resultD bson.D
+	testDecodeError(c, b, &resultD)
+}
+{{end}}
+{{end}}
+`
+	tmpl, err := template.New("").Parse(content)
+	if err != nil {
+		return nil, err
+	}
+	return tmpl, nil
+}
+
+func cleanupFuncName(name string) string {
+	return strings.Map(func(r rune) rune {
+		if (r >= 48 && r <= 57) || (r >= 65 && r <= 90) || (r >= 97 && r <= 122) {
+			return r
+		}
+		return '_'
+	}, name)
+}
+
+type testDef struct {
+	Description  string         `json:"description"`
+	BsonType     string         `json:"bson_type"`
+	TestKey      string         `json:"test_key"`
+	Valid        []*valid       `json:"valid"`
+	DecodeErrors []*decodeError `json:"decodeErrors"`
+	Deprecated   bool           `json:"deprecated"`
+}
+
+func (t *testDef) GoType() string {
+	switch t.BsonType {
+	case "0x01":
+		return "float64"
+	case "0x02":
+		return "string"
+	case "0x03":
+		return "bson.D"
+	case "0x04":
+		return "[]interface{}"
+	case "0x05":
+		return "[]byte"
+	case "0x07":
+		return "bson.ObjectId"
+	case "0x08":
+		return "bool"
+	case "0x09":
+		return "time.Time"
+	case "0x0E":
+		return "string"
+	case "0x10":
+		return "int32"
+	case "0x12":
+		return "int64"
+	case "0x13":
+		return "bson.Decimal"
+	default:
+		return "interface{}"
+	}
+}
+
+type valid struct {
+	Description   string `json:"description"`
+	Bson          string `json:"bson"`
+	CanonicalBson string `json:"canonical_bson"`
+
+	Name       string
+	StructTest bool
+	TestDef    *testDef
+}
+
+type decodeError struct {
+	Description string `json:"description"`
+	Bson        string `json:"bson"`
+
+	Name string
+}
diff --git a/go/vendor/github.com/globalsign/mgo/bson/compatibility.go b/go/vendor/github.com/globalsign/mgo/bson/compatibility.go
new file mode 100644
index 0000000..66efd46
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/compatibility.go
@@ -0,0 +1,29 @@
+package bson
+
+// Current state of the JSON tag fallback option.
+var useJSONTagFallback = false
+var useRespectNilValues = false
+
+// SetJSONTagFallback enables or disables the JSON-tag fallback for structure tagging. When this is enabled, structures
+// without BSON tags on a field will fall-back to using the JSON tag (if present).
+func SetJSONTagFallback(state bool) {
+	useJSONTagFallback = state
+}
+
+// JSONTagFallbackState returns the current status of the JSON tag fallback compatability option. See SetJSONTagFallback
+// for more information.
+func JSONTagFallbackState() bool {
+	return useJSONTagFallback
+}
+
+// SetRespectNilValues enables or disables serializing nil slices or maps to `null` values.
+// In other words it enables `encoding/json` compatible behaviour.
+func SetRespectNilValues(state bool) {
+	useRespectNilValues = state
+}
+
+// RespectNilValuesState returns the current status of the JSON nil slices and maps fallback compatibility option.
+// See SetRespectNilValues for more information.
+func RespectNilValuesState() bool {
+	return useRespectNilValues
+}
diff --git a/go/vendor/github.com/globalsign/mgo/bson/decimal.go b/go/vendor/github.com/globalsign/mgo/bson/decimal.go
new file mode 100644
index 0000000..672ba18
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/decimal.go
@@ -0,0 +1,312 @@
+// BSON library for Go
+//
+// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package bson
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// Decimal128 holds decimal128 BSON values.
+type Decimal128 struct {
+	h, l uint64
+}
+
+func (d Decimal128) String() string {
+	var pos int     // positive sign
+	var e int       // exponent
+	var h, l uint64 // significand high/low
+
+	if d.h>>63&1 == 0 {
+		pos = 1
+	}
+
+	switch d.h >> 58 & (1<<5 - 1) {
+	case 0x1F:
+		return "NaN"
+	case 0x1E:
+		return "-Inf"[pos:]
+	}
+
+	l = d.l
+	if d.h>>61&3 == 3 {
+		// Bits: 1*sign 2*ignored 14*exponent 111*significand.
+		// Implicit 0b100 prefix in significand.
+		e = int(d.h>>47&(1<<14-1)) - 6176
+		//h = 4<<47 | d.h&(1<<47-1)
+		// Spec says all of these values are out of range.
+		h, l = 0, 0
+	} else {
+		// Bits: 1*sign 14*exponent 113*significand
+		e = int(d.h>>49&(1<<14-1)) - 6176
+		h = d.h & (1<<49 - 1)
+	}
+
+	// Would be handled by the logic below, but that's trivial and common.
+	if h == 0 && l == 0 && e == 0 {
+		return "-0"[pos:]
+	}
+
+	var repr [48]byte // Loop 5 times over 9 digits plus dot, negative sign, and leading zero.
+	var last = len(repr)
+	var i = len(repr)
+	var dot = len(repr) + e
+	var rem uint32
+Loop:
+	for d9 := 0; d9 < 5; d9++ {
+		h, l, rem = divmod(h, l, 1e9)
+		for d1 := 0; d1 < 9; d1++ {
+			// Handle "-0.0", "0.00123400", "-1.00E-6", "1.050E+3", etc.
+			if i < len(repr) && (dot == i || l == 0 && h == 0 && rem > 0 && rem < 10 && (dot < i-6 || e > 0)) {
+				e += len(repr) - i
+				i--
+				repr[i] = '.'
+				last = i - 1
+				dot = len(repr) // Unmark.
+			}
+			c := '0' + byte(rem%10)
+			rem /= 10
+			i--
+			repr[i] = c
+			// Handle "0E+3", "1E+3", etc.
+			if l == 0 && h == 0 && rem == 0 && i == len(repr)-1 && (dot < i-5 || e > 0) {
+				last = i
+				break Loop
+			}
+			if c != '0' {
+				last = i
+			}
+			// Break early. Works without it, but why.
+			if dot > i && l == 0 && h == 0 && rem == 0 {
+				break Loop
+			}
+		}
+	}
+	repr[last-1] = '-'
+	last--
+
+	if e > 0 {
+		return string(repr[last+pos:]) + "E+" + strconv.Itoa(e)
+	}
+	if e < 0 {
+		return string(repr[last+pos:]) + "E" + strconv.Itoa(e)
+	}
+	return string(repr[last+pos:])
+}
+
+func divmod(h, l uint64, div uint32) (qh, ql uint64, rem uint32) {
+	div64 := uint64(div)
+	a := h >> 32
+	aq := a / div64
+	ar := a % div64
+	b := ar<<32 + h&(1<<32-1)
+	bq := b / div64
+	br := b % div64
+	c := br<<32 + l>>32
+	cq := c / div64
+	cr := c % div64
+	d := cr<<32 + l&(1<<32-1)
+	dq := d / div64
+	dr := d % div64
+	return (aq<<32 | bq), (cq<<32 | dq), uint32(dr)
+}
+
+var dNaN = Decimal128{0x1F << 58, 0}
+var dPosInf = Decimal128{0x1E << 58, 0}
+var dNegInf = Decimal128{0x3E << 58, 0}
+
+func dErr(s string) (Decimal128, error) {
+	return dNaN, fmt.Errorf("cannot parse %q as a decimal128", s)
+}
+
+// ParseDecimal128 parse a string and return the corresponding value as
+// a decimal128
+func ParseDecimal128(s string) (Decimal128, error) {
+	orig := s
+	if s == "" {
+		return dErr(orig)
+	}
+	neg := s[0] == '-'
+	if neg || s[0] == '+' {
+		s = s[1:]
+	}
+
+	if (len(s) == 3 || len(s) == 8) && (s[0] == 'N' || s[0] == 'n' || s[0] == 'I' || s[0] == 'i') {
+		if s == "NaN" || s == "nan" || strings.EqualFold(s, "nan") {
+			return dNaN, nil
+		}
+		if s == "Inf" || s == "inf" || strings.EqualFold(s, "inf") || strings.EqualFold(s, "infinity") {
+			if neg {
+				return dNegInf, nil
+			}
+			return dPosInf, nil
+		}
+		return dErr(orig)
+	}
+
+	var h, l uint64
+	var e int
+
+	var add, ovr uint32
+	var mul uint32 = 1
+	var dot = -1
+	var digits = 0
+	var i = 0
+	for i < len(s) {
+		c := s[i]
+		if mul == 1e9 {
+			h, l, ovr = muladd(h, l, mul, add)
+			mul, add = 1, 0
+			if ovr > 0 || h&((1<<15-1)<<49) > 0 {
+				return dErr(orig)
+			}
+		}
+		if c >= '0' && c <= '9' {
+			i++
+			if c > '0' || digits > 0 {
+				digits++
+			}
+			if digits > 34 {
+				if c == '0' {
+					// Exact rounding.
+					e++
+					continue
+				}
+				return dErr(orig)
+			}
+			mul *= 10
+			add *= 10
+			add += uint32(c - '0')
+			continue
+		}
+		if c == '.' {
+			i++
+			if dot >= 0 || i == 1 && len(s) == 1 {
+				return dErr(orig)
+			}
+			if i == len(s) {
+				break
+			}
+			if s[i] < '0' || s[i] > '9' || e > 0 {
+				return dErr(orig)
+			}
+			dot = i
+			continue
+		}
+		break
+	}
+	if i == 0 {
+		return dErr(orig)
+	}
+	if mul > 1 {
+		h, l, ovr = muladd(h, l, mul, add)
+		if ovr > 0 || h&((1<<15-1)<<49) > 0 {
+			return dErr(orig)
+		}
+	}
+	if dot >= 0 {
+		e += dot - i
+	}
+	if i+1 < len(s) && (s[i] == 'E' || s[i] == 'e') {
+		i++
+		eneg := s[i] == '-'
+		if eneg || s[i] == '+' {
+			i++
+			if i == len(s) {
+				return dErr(orig)
+			}
+		}
+		n := 0
+		for i < len(s) && n < 1e4 {
+			c := s[i]
+			i++
+			if c < '0' || c > '9' {
+				return dErr(orig)
+			}
+			n *= 10
+			n += int(c - '0')
+		}
+		if eneg {
+			n = -n
+		}
+		e += n
+		for e < -6176 {
+			// Subnormal.
+			var div uint32 = 1
+			for div < 1e9 && e < -6176 {
+				div *= 10
+				e++
+			}
+			var rem uint32
+			h, l, rem = divmod(h, l, div)
+			if rem > 0 {
+				return dErr(orig)
+			}
+		}
+		for e > 6111 {
+			// Clamped.
+			var mul uint32 = 1
+			for mul < 1e9 && e > 6111 {
+				mul *= 10
+				e--
+			}
+			h, l, ovr = muladd(h, l, mul, 0)
+			if ovr > 0 || h&((1<<15-1)<<49) > 0 {
+				return dErr(orig)
+			}
+		}
+		if e < -6176 || e > 6111 {
+			return dErr(orig)
+		}
+	}
+
+	if i < len(s) {
+		return dErr(orig)
+	}
+
+	h |= uint64(e+6176) & uint64(1<<14-1) << 49
+	if neg {
+		h |= 1 << 63
+	}
+	return Decimal128{h, l}, nil
+}
+
+func muladd(h, l uint64, mul uint32, add uint32) (resh, resl uint64, overflow uint32) {
+	mul64 := uint64(mul)
+	a := mul64 * (l & (1<<32 - 1))
+	b := a>>32 + mul64*(l>>32)
+	c := b>>32 + mul64*(h&(1<<32-1))
+	d := c>>32 + mul64*(h>>32)
+
+	a = a&(1<<32-1) + uint64(add)
+	b = b&(1<<32-1) + a>>32
+	c = c&(1<<32-1) + b>>32
+	d = d&(1<<32-1) + c>>32
+
+	return (d<<32 | c&(1<<32-1)), (b<<32 | a&(1<<32-1)), uint32(d >> 32)
+}
diff --git a/go/vendor/github.com/globalsign/mgo/bson/decode.go b/go/vendor/github.com/globalsign/mgo/bson/decode.go
new file mode 100644
index 0000000..658856a
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/decode.go
@@ -0,0 +1,1055 @@
+// BSON library for Go
+//
+// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// gobson - BSON library for Go.
+
+package bson
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"net/url"
+	"reflect"
+	"strconv"
+	"sync"
+	"time"
+)
+
+type decoder struct {
+	in      []byte
+	i       int
+	docType reflect.Type
+}
+
+var typeM = reflect.TypeOf(M{})
+
+func newDecoder(in []byte) *decoder {
+	return &decoder{in, 0, typeM}
+}
+
+// --------------------------------------------------------------------------
+// Some helper functions.
+
+func corrupted() {
+	panic("Document is corrupted")
+}
+
+// --------------------------------------------------------------------------
+// Unmarshaling of documents.
+
+const (
+	setterUnknown = iota
+	setterNone
+	setterType
+	setterAddr
+)
+
+var setterStyles map[reflect.Type]int
+var setterIface reflect.Type
+var setterMutex sync.RWMutex
+
+func init() {
+	var iface Setter
+	setterIface = reflect.TypeOf(&iface).Elem()
+	setterStyles = make(map[reflect.Type]int)
+}
+
+func setterStyle(outt reflect.Type) int {
+	setterMutex.RLock()
+	style := setterStyles[outt]
+	setterMutex.RUnlock()
+	if style != setterUnknown {
+		return style
+	}
+
+	setterMutex.Lock()
+	defer setterMutex.Unlock()
+	if outt.Implements(setterIface) {
+		style = setterType
+	} else if reflect.PtrTo(outt).Implements(setterIface) {
+		style = setterAddr
+	} else {
+		style = setterNone
+	}
+	setterStyles[outt] = style
+	return style
+}
+
+func getSetter(outt reflect.Type, out reflect.Value) Setter {
+	style := setterStyle(outt)
+	if style == setterNone {
+		return nil
+	}
+	if style == setterAddr {
+		if !out.CanAddr() {
+			return nil
+		}
+		out = out.Addr()
+	} else if outt.Kind() == reflect.Ptr && out.IsNil() {
+		out.Set(reflect.New(outt.Elem()))
+	}
+	return out.Interface().(Setter)
+}
+
+func clearMap(m reflect.Value) {
+	var none reflect.Value
+	for _, k := range m.MapKeys() {
+		m.SetMapIndex(k, none)
+	}
+}
+
+func (d *decoder) readDocTo(out reflect.Value) {
+	var elemType reflect.Type
+	outt := out.Type()
+	outk := outt.Kind()
+
+	for {
+		if outk == reflect.Ptr && out.IsNil() {
+			out.Set(reflect.New(outt.Elem()))
+		}
+		if setter := getSetter(outt, out); setter != nil {
+			raw := d.readRaw(ElementDocument)
+			err := setter.SetBSON(raw)
+			if _, ok := err.(*TypeError); err != nil && !ok {
+				panic(err)
+			}
+			return
+		}
+		if outk == reflect.Ptr {
+			out = out.Elem()
+			outt = out.Type()
+			outk = out.Kind()
+			continue
+		}
+		break
+	}
+
+	var fieldsMap map[string]fieldInfo
+	var inlineMap reflect.Value
+	if outt == typeRaw {
+		out.Set(reflect.ValueOf(d.readRaw(ElementDocument)))
+		return
+	}
+
+	origout := out
+	if outk == reflect.Interface {
+		if d.docType.Kind() == reflect.Map {
+			mv := reflect.MakeMap(d.docType)
+			out.Set(mv)
+			out = mv
+		} else {
+			dv := reflect.New(d.docType).Elem()
+			out.Set(dv)
+			out = dv
+		}
+		outt = out.Type()
+		outk = outt.Kind()
+	}
+
+	docType := d.docType
+	keyType := typeString
+	convertKey := false
+	switch outk {
+	case reflect.Map:
+		keyType = outt.Key()
+		if keyType != typeString {
+			convertKey = true
+		}
+		elemType = outt.Elem()
+		if elemType == typeIface {
+			d.docType = outt
+		}
+		if out.IsNil() {
+			out.Set(reflect.MakeMap(out.Type()))
+		} else if out.Len() > 0 {
+			clearMap(out)
+		}
+	case reflect.Struct:
+		sinfo, err := getStructInfo(out.Type())
+		if err != nil {
+			panic(err)
+		}
+		fieldsMap = sinfo.FieldsMap
+		out.Set(sinfo.Zero)
+		if sinfo.InlineMap != -1 {
+			inlineMap = out.Field(sinfo.InlineMap)
+			if !inlineMap.IsNil() && inlineMap.Len() > 0 {
+				clearMap(inlineMap)
+			}
+			elemType = inlineMap.Type().Elem()
+			if elemType == typeIface {
+				d.docType = inlineMap.Type()
+			}
+		}
+	case reflect.Slice:
+		switch outt.Elem() {
+		case typeDocElem:
+			origout.Set(d.readDocElems(outt))
+			return
+		case typeRawDocElem:
+			origout.Set(d.readRawDocElems(outt))
+			return
+		}
+		fallthrough
+	default:
+		panic("Unsupported document type for unmarshalling: " + out.Type().String())
+	}
+
+	end := int(d.readInt32())
+	end += d.i - 4
+	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
+		corrupted()
+	}
+	for d.in[d.i] != '\x00' {
+		kind := d.readByte()
+		name := d.readCStr()
+		if d.i >= end {
+			corrupted()
+		}
+
+		switch outk {
+		case reflect.Map:
+			e := reflect.New(elemType).Elem()
+			if d.readElemTo(e, kind) {
+				k := reflect.ValueOf(name)
+				if convertKey {
+					mapKeyType := out.Type().Key()
+					mapKeyKind := mapKeyType.Kind()
+
+					switch mapKeyKind {
+					case reflect.Int:
+						fallthrough
+					case reflect.Int8:
+						fallthrough
+					case reflect.Int16:
+						fallthrough
+					case reflect.Int32:
+						fallthrough
+					case reflect.Int64:
+						fallthrough
+					case reflect.Uint:
+						fallthrough
+					case reflect.Uint8:
+						fallthrough
+					case reflect.Uint16:
+						fallthrough
+					case reflect.Uint32:
+						fallthrough
+					case reflect.Uint64:
+						fallthrough
+					case reflect.Float32:
+						fallthrough
+					case reflect.Float64:
+						parsed := d.parseMapKeyAsFloat(k, mapKeyKind)
+						k = reflect.ValueOf(parsed)
+					case reflect.String:
+						mapKeyType = keyType
+					default:
+						panic("BSON map must have string or decimal keys. Got: " + outt.String())
+					}
+
+					k = k.Convert(mapKeyType)
+				}
+				out.SetMapIndex(k, e)
+			}
+		case reflect.Struct:
+			if info, ok := fieldsMap[name]; ok {
+				if info.Inline == nil {
+					d.readElemTo(out.Field(info.Num), kind)
+				} else {
+					d.readElemTo(out.FieldByIndex(info.Inline), kind)
+				}
+			} else if inlineMap.IsValid() {
+				if inlineMap.IsNil() {
+					inlineMap.Set(reflect.MakeMap(inlineMap.Type()))
+				}
+				e := reflect.New(elemType).Elem()
+				if d.readElemTo(e, kind) {
+					inlineMap.SetMapIndex(reflect.ValueOf(name), e)
+				}
+			} else {
+				d.dropElem(kind)
+			}
+		case reflect.Slice:
+		}
+
+		if d.i >= end {
+			corrupted()
+		}
+	}
+	d.i++ // '\x00'
+	if d.i != end {
+		corrupted()
+	}
+	d.docType = docType
+}
+
+func (decoder) parseMapKeyAsFloat(k reflect.Value, mapKeyKind reflect.Kind) float64 {
+	parsed, err := strconv.ParseFloat(k.String(), 64)
+	if err != nil {
+		panic("Map key is defined to be a decimal type (" + mapKeyKind.String() + ") but got error " +
+			err.Error())
+	}
+
+	return parsed
+}
+
+func (d *decoder) readArrayDocTo(out reflect.Value) {
+	end := int(d.readInt32())
+	end += d.i - 4
+	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
+		corrupted()
+	}
+	i := 0
+	l := out.Len()
+	for d.in[d.i] != '\x00' {
+		if i >= l {
+			panic("Length mismatch on array field")
+		}
+		kind := d.readByte()
+		for d.i < end && d.in[d.i] != '\x00' {
+			d.i++
+		}
+		if d.i >= end {
+			corrupted()
+		}
+		d.i++
+		d.readElemTo(out.Index(i), kind)
+		if d.i >= end {
+			corrupted()
+		}
+		i++
+	}
+	if i != l {
+		panic("Length mismatch on array field")
+	}
+	d.i++ // '\x00'
+	if d.i != end {
+		corrupted()
+	}
+}
+
+func (d *decoder) readSliceDoc(t reflect.Type) interface{} {
+	tmp := make([]reflect.Value, 0, 8)
+	elemType := t.Elem()
+	if elemType == typeRawDocElem {
+		d.dropElem(ElementArray)
+		return reflect.Zero(t).Interface()
+	}
+	if elemType == typeRaw {
+		return d.readSliceOfRaw()
+	}
+
+	end := int(d.readInt32())
+	end += d.i - 4
+	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
+		corrupted()
+	}
+	for d.in[d.i] != '\x00' {
+		kind := d.readByte()
+		for d.i < end && d.in[d.i] != '\x00' {
+			d.i++
+		}
+		if d.i >= end {
+			corrupted()
+		}
+		d.i++
+		e := reflect.New(elemType).Elem()
+		if d.readElemTo(e, kind) {
+			tmp = append(tmp, e)
+		}
+		if d.i >= end {
+			corrupted()
+		}
+	}
+	d.i++ // '\x00'
+	if d.i != end {
+		corrupted()
+	}
+
+	n := len(tmp)
+	slice := reflect.MakeSlice(t, n, n)
+	for i := 0; i != n; i++ {
+		slice.Index(i).Set(tmp[i])
+	}
+	return slice.Interface()
+}
+
+func BSONElementSize(kind byte, offset int, buffer []byte) (int, error) {
+	switch kind {
+	case ElementFloat64: // Float64
+		return 8, nil
+	case ElementJavaScriptWithoutScope: // JavaScript without scope
+		fallthrough
+	case ElementSymbol: // Symbol
+		fallthrough
+	case ElementString: // UTF-8 string
+		size, err := getSize(offset, buffer)
+		if err != nil {
+			return 0, err
+		}
+		if size < 1 {
+			return 0, errors.New("String size can't be less then one byte")
+		}
+		size += 4
+		if offset+size > len(buffer) {
+			return 0, io.ErrUnexpectedEOF
+		}
+		if buffer[offset+size-1] != 0 {
+			return 0, errors.New("Invalid string: non zero-terminated")
+		}
+		return size, nil
+	case ElementArray: // Array
+		fallthrough
+	case ElementDocument: // Document
+		size, err := getSize(offset, buffer)
+		if err != nil {
+			return 0, err
+		}
+		if size < 5 {
+			return 0, errors.New("Declared document size is too small")
+		}
+		return size, nil
+	case ElementBinary: // Binary
+		size, err := getSize(offset, buffer)
+		if err != nil {
+			return 0, err
+		}
+		if size < 0 {
+			return 0, errors.New("Binary data size can't be negative")
+		}
+		return size + 5, nil
+	case Element06: // Undefined (obsolete, but still seen in the wild)
+		return 0, nil
+	case ElementObjectId: // ObjectId
+		return 12, nil
+	case ElementBool: // Bool
+		return 1, nil
+	case ElementDatetime: // Timestamp
+		return 8, nil
+	case ElementNil: // Nil
+		return 0, nil
+	case ElementRegEx: // RegEx
+		end := offset
+		for i := 0; i < 2; i++ {
+			for end < len(buffer) && buffer[end] != '\x00' {
+				end++
+			}
+			end++
+		}
+		if end > len(buffer) {
+			return 0, io.ErrUnexpectedEOF
+		}
+		return end - offset, nil
+	case ElementDBPointer: // DBPointer
+		size, err := getSize(offset, buffer)
+		if err != nil {
+			return 0, err
+		}
+		if size < 1 {
+			return 0, errors.New("String size can't be less then one byte")
+		}
+		return size + 12 + 4, nil
+	case ElementJavaScriptWithScope: // JavaScript with scope
+		size, err := getSize(offset, buffer)
+		if err != nil {
+			return 0, err
+		}
+		if size < 4+5+5 {
+			return 0, errors.New("Declared document element is too small")
+		}
+		return size, nil
+	case ElementInt32: // Int32
+		return 4, nil
+	case ElementTimestamp: // Mongo-specific timestamp
+		return 8, nil
+	case ElementInt64: // Int64
+		return 8, nil
+	case ElementDecimal128: // Decimal128
+		return 16, nil
+	case ElementMaxKey: // Max key
+		return 0, nil
+	case ElementMinKey: // Min key
+		return 0, nil
+	default:
+		return 0, errors.New(fmt.Sprintf("Unknown element kind (0x%02X)", kind))
+	}
+}
+
+func (d *decoder) readRaw(kind byte) Raw {
+	size, err := BSONElementSize(kind, d.i, d.in)
+	if err != nil {
+		corrupted()
+	}
+	if d.i+size > len(d.in) {
+		corrupted()
+	}
+	d.i += size
+	return Raw{
+		Kind: kind,
+		Data: d.in[d.i-size : d.i],
+	}
+}
+
+func (d *decoder) readSliceOfRaw() interface{} {
+	tmp := make([]Raw, 0, 8)
+	end := int(d.readInt32())
+	end += d.i - 4
+	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
+		corrupted()
+	}
+	for d.in[d.i] != '\x00' {
+		kind := d.readByte()
+		for d.i < end && d.in[d.i] != '\x00' {
+			d.i++
+		}
+		if d.i >= end {
+			corrupted()
+		}
+		d.i++
+		e := d.readRaw(kind)
+		tmp = append(tmp, e)
+		if d.i >= end {
+			corrupted()
+		}
+	}
+	d.i++ // '\x00'
+	if d.i != end {
+		corrupted()
+	}
+	return tmp
+}
+
+var typeSlice = reflect.TypeOf([]interface{}{})
+var typeIface = typeSlice.Elem()
+
+func (d *decoder) readDocElems(typ reflect.Type) reflect.Value {
+	docType := d.docType
+	d.docType = typ
+	slice := make([]DocElem, 0, 8)
+	d.readDocWith(func(kind byte, name string) {
+		e := DocElem{Name: name}
+		v := reflect.ValueOf(&e.Value)
+		if d.readElemTo(v.Elem(), kind) {
+			slice = append(slice, e)
+		}
+	})
+	slicev := reflect.New(typ).Elem()
+	slicev.Set(reflect.ValueOf(slice))
+	d.docType = docType
+	return slicev
+}
+
+func (d *decoder) readRawDocElems(typ reflect.Type) reflect.Value {
+	docType := d.docType
+	d.docType = typ
+	slice := make([]RawDocElem, 0, 8)
+	d.readDocWith(func(kind byte, name string) {
+		e := RawDocElem{Name: name, Value: d.readRaw(kind)}
+		slice = append(slice, e)
+	})
+	slicev := reflect.New(typ).Elem()
+	slicev.Set(reflect.ValueOf(slice))
+	d.docType = docType
+	return slicev
+}
+
+func (d *decoder) readDocWith(f func(kind byte, name string)) {
+	end := int(d.readInt32())
+	end += d.i - 4
+	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
+		corrupted()
+	}
+	for d.in[d.i] != '\x00' {
+		kind := d.readByte()
+		name := d.readCStr()
+		if d.i >= end {
+			corrupted()
+		}
+		f(kind, name)
+		if d.i >= end {
+			corrupted()
+		}
+	}
+	d.i++ // '\x00'
+	if d.i != end {
+		corrupted()
+	}
+}
+
+// --------------------------------------------------------------------------
+// Unmarshaling of individual elements within a document.
+func (d *decoder) dropElem(kind byte) {
+	size, err := BSONElementSize(kind, d.i, d.in)
+	if err != nil {
+		corrupted()
+	}
+	if d.i+size > len(d.in) {
+		corrupted()
+	}
+	d.i += size
+}
+
+// Attempt to decode an element from the document and put it into out.
+// If the types are not compatible, the returned ok value will be
+// false and out will be unchanged.
+func (d *decoder) readElemTo(out reflect.Value, kind byte) (good bool) {
+	outt := out.Type()
+
+	if outt == typeRaw {
+		out.Set(reflect.ValueOf(d.readRaw(kind)))
+		return true
+	}
+
+	if outt == typeRawPtr {
+		raw := d.readRaw(kind)
+		out.Set(reflect.ValueOf(&raw))
+		return true
+	}
+
+	if kind == ElementDocument {
+		// Delegate unmarshaling of documents.
+		outt := out.Type()
+		outk := out.Kind()
+		switch outk {
+		case reflect.Interface, reflect.Ptr, reflect.Struct, reflect.Map:
+			d.readDocTo(out)
+			return true
+		}
+		if setterStyle(outt) != setterNone {
+			d.readDocTo(out)
+			return true
+		}
+		if outk == reflect.Slice {
+			switch outt.Elem() {
+			case typeDocElem:
+				out.Set(d.readDocElems(outt))
+			case typeRawDocElem:
+				out.Set(d.readRawDocElems(outt))
+			default:
+				d.dropElem(kind)
+			}
+			return true
+		}
+		d.dropElem(kind)
+		return true
+	}
+
+	if setter := getSetter(outt, out); setter != nil {
+		err := setter.SetBSON(d.readRaw(kind))
+		if err == ErrSetZero {
+			out.Set(reflect.Zero(outt))
+			return true
+		}
+		if err == nil {
+			return true
+		}
+		if _, ok := err.(*TypeError); !ok {
+			panic(err)
+		}
+		return false
+	}
+
+	var in interface{}
+
+	switch kind {
+	case ElementFloat64:
+		in = d.readFloat64()
+	case ElementString:
+		in = d.readStr()
+	case ElementDocument:
+		panic("Can't happen. Handled above.")
+	case ElementArray:
+		outt := out.Type()
+		if setterStyle(outt) != setterNone {
+			// Skip the value so its data is handed to the setter below.
+			d.dropElem(kind)
+			break
+		}
+		for outt.Kind() == reflect.Ptr {
+			outt = outt.Elem()
+		}
+		switch outt.Kind() {
+		case reflect.Array:
+			d.readArrayDocTo(out)
+			return true
+		case reflect.Slice:
+			in = d.readSliceDoc(outt)
+		default:
+			in = d.readSliceDoc(typeSlice)
+		}
+	case ElementBinary:
+		b := d.readBinary()
+		if b.Kind == BinaryGeneric || b.Kind == BinaryBinaryOld {
+			in = b.Data
+		} else {
+			in = b
+		}
+	case Element06: // Undefined (obsolete, but still seen in the wild)
+		in = Undefined
+	case ElementObjectId:
+		in = ObjectId(d.readBytes(12))
+	case ElementBool:
+		in = d.readBool()
+	case ElementDatetime: // Timestamp
+		// MongoDB handles timestamps as milliseconds.
+		i := d.readInt64()
+		if i == -62135596800000 {
+			in = time.Time{} // In UTC for convenience.
+		} else {
+			in = time.Unix(i/1e3, i%1e3*1e6).UTC()
+		}
+	case ElementNil:
+		in = nil
+	case ElementRegEx:
+		in = d.readRegEx()
+	case ElementDBPointer:
+		in = DBPointer{Namespace: d.readStr(), Id: ObjectId(d.readBytes(12))}
+	case ElementJavaScriptWithoutScope:
+		in = JavaScript{Code: d.readStr()}
+	case ElementSymbol:
+		in = Symbol(d.readStr())
+	case ElementJavaScriptWithScope:
+		start := d.i
+		l := int(d.readInt32())
+		js := JavaScript{d.readStr(), make(M)}
+		d.readDocTo(reflect.ValueOf(js.Scope))
+		if d.i != start+l {
+			corrupted()
+		}
+		in = js
+	case ElementInt32:
+		in = int(d.readInt32())
+	case ElementTimestamp: // Mongo-specific timestamp
+		in = MongoTimestamp(d.readInt64())
+	case ElementInt64:
+		switch out.Type() {
+		case typeTimeDuration:
+			in = time.Duration(time.Duration(d.readInt64()) * time.Millisecond)
+		default:
+			in = d.readInt64()
+		}
+	case ElementDecimal128:
+		in = Decimal128{
+			l: uint64(d.readInt64()),
+			h: uint64(d.readInt64()),
+		}
+	case ElementMaxKey:
+		in = MaxKey
+	case ElementMinKey:
+		in = MinKey
+	default:
+		panic(fmt.Sprintf("Unknown element kind (0x%02X)", kind))
+	}
+
+	if in == nil {
+		out.Set(reflect.Zero(outt))
+		return true
+	}
+
+	outk := outt.Kind()
+
+	// Dereference and initialize pointer if necessary.
+	first := true
+	for outk == reflect.Ptr {
+		if !out.IsNil() {
+			out = out.Elem()
+		} else {
+			elem := reflect.New(outt.Elem())
+			if first {
+				// Only set if value is compatible.
+				first = false
+				defer func(out, elem reflect.Value) {
+					if good {
+						out.Set(elem)
+					}
+				}(out, elem)
+			} else {
+				out.Set(elem)
+			}
+			out = elem
+		}
+		outt = out.Type()
+		outk = outt.Kind()
+	}
+
+	inv := reflect.ValueOf(in)
+	if outt == inv.Type() {
+		out.Set(inv)
+		return true
+	}
+
+	switch outk {
+	case reflect.Interface:
+		out.Set(inv)
+		return true
+	case reflect.String:
+		switch inv.Kind() {
+		case reflect.String:
+			out.SetString(inv.String())
+			return true
+		case reflect.Slice:
+			if b, ok := in.([]byte); ok {
+				out.SetString(string(b))
+				return true
+			}
+		case reflect.Int, reflect.Int64:
+			if outt == typeJSONNumber {
+				out.SetString(strconv.FormatInt(inv.Int(), 10))
+				return true
+			}
+		case reflect.Float64:
+			if outt == typeJSONNumber {
+				out.SetString(strconv.FormatFloat(inv.Float(), 'f', -1, 64))
+				return true
+			}
+		}
+	case reflect.Slice, reflect.Array:
+		// Remember, array (0x04) slices are built with the correct
+		// element type.  If we are here, must be a cross BSON kind
+		// conversion (e.g. 0x05 unmarshalling on string).
+		if outt.Elem().Kind() != reflect.Uint8 {
+			break
+		}
+		switch inv.Kind() {
+		case reflect.String:
+			slice := []byte(inv.String())
+			out.Set(reflect.ValueOf(slice))
+			return true
+		case reflect.Slice:
+			switch outt.Kind() {
+			case reflect.Array:
+				reflect.Copy(out, inv)
+			case reflect.Slice:
+				out.SetBytes(inv.Bytes())
+			}
+			return true
+		}
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		switch inv.Kind() {
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			out.SetInt(inv.Int())
+			return true
+		case reflect.Float32, reflect.Float64:
+			out.SetInt(int64(inv.Float()))
+			return true
+		case reflect.Bool:
+			if inv.Bool() {
+				out.SetInt(1)
+			} else {
+				out.SetInt(0)
+			}
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+			panic("can't happen: no uint types in BSON (!?)")
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		switch inv.Kind() {
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			out.SetUint(uint64(inv.Int()))
+			return true
+		case reflect.Float32, reflect.Float64:
+			out.SetUint(uint64(inv.Float()))
+			return true
+		case reflect.Bool:
+			if inv.Bool() {
+				out.SetUint(1)
+			} else {
+				out.SetUint(0)
+			}
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+			panic("Can't happen. No uint types in BSON.")
+		}
+	case reflect.Float32, reflect.Float64:
+		switch inv.Kind() {
+		case reflect.Float32, reflect.Float64:
+			out.SetFloat(inv.Float())
+			return true
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			out.SetFloat(float64(inv.Int()))
+			return true
+		case reflect.Bool:
+			if inv.Bool() {
+				out.SetFloat(1)
+			} else {
+				out.SetFloat(0)
+			}
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+			panic("Can't happen. No uint types in BSON?")
+		}
+	case reflect.Bool:
+		switch inv.Kind() {
+		case reflect.Bool:
+			out.SetBool(inv.Bool())
+			return true
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			out.SetBool(inv.Int() != 0)
+			return true
+		case reflect.Float32, reflect.Float64:
+			out.SetBool(inv.Float() != 0)
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+			panic("Can't happen. No uint types in BSON?")
+		}
+	case reflect.Struct:
+		if outt == typeURL && inv.Kind() == reflect.String {
+			u, err := url.Parse(inv.String())
+			if err != nil {
+				panic(err)
+			}
+			out.Set(reflect.ValueOf(u).Elem())
+			return true
+		}
+		if outt == typeBinary {
+			if b, ok := in.([]byte); ok {
+				out.Set(reflect.ValueOf(Binary{Data: b}))
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
+// --------------------------------------------------------------------------
+// Parsers of basic types.
+
+func (d *decoder) readRegEx() RegEx {
+	re := RegEx{}
+	re.Pattern = d.readCStr()
+	re.Options = d.readCStr()
+	return re
+}
+
+func (d *decoder) readBinary() Binary {
+	l := d.readInt32()
+	b := Binary{}
+	b.Kind = d.readByte()
+	if b.Kind == BinaryBinaryOld && l > 4 {
+		// Weird obsolete format with redundant length.
+		rl := d.readInt32()
+		if rl != l-4 {
+			corrupted()
+		}
+		l = rl
+	}
+	b.Data = d.readBytes(l)
+	return b
+}
+
+func (d *decoder) readStr() string {
+	l := d.readInt32()
+	b := d.readBytes(l - 1)
+	if d.readByte() != '\x00' {
+		corrupted()
+	}
+	return string(b)
+}
+
+func (d *decoder) readCStr() string {
+	start := d.i
+	end := start
+	l := len(d.in)
+	for ; end != l; end++ {
+		if d.in[end] == '\x00' {
+			break
+		}
+	}
+	d.i = end + 1
+	if d.i > l {
+		corrupted()
+	}
+	return string(d.in[start:end])
+}
+
+func (d *decoder) readBool() bool {
+	b := d.readByte()
+	if b == 0 {
+		return false
+	}
+	if b == 1 {
+		return true
+	}
+	panic(fmt.Sprintf("encoded boolean must be 1 or 0, found %d", b))
+}
+
+func (d *decoder) readFloat64() float64 {
+	return math.Float64frombits(uint64(d.readInt64()))
+}
+
+func (d *decoder) readInt32() int32 {
+	b := d.readBytes(4)
+	return int32((uint32(b[0]) << 0) |
+		(uint32(b[1]) << 8) |
+		(uint32(b[2]) << 16) |
+		(uint32(b[3]) << 24))
+}
+
+func getSize(offset int, b []byte) (int, error) {
+	if offset+4 > len(b) {
+		return 0, io.ErrUnexpectedEOF
+	}
+	return int((uint32(b[offset]) << 0) |
+		(uint32(b[offset+1]) << 8) |
+		(uint32(b[offset+2]) << 16) |
+		(uint32(b[offset+3]) << 24)), nil
+}
+
+func (d *decoder) readInt64() int64 {
+	b := d.readBytes(8)
+	return int64((uint64(b[0]) << 0) |
+		(uint64(b[1]) << 8) |
+		(uint64(b[2]) << 16) |
+		(uint64(b[3]) << 24) |
+		(uint64(b[4]) << 32) |
+		(uint64(b[5]) << 40) |
+		(uint64(b[6]) << 48) |
+		(uint64(b[7]) << 56))
+}
+
+func (d *decoder) readByte() byte {
+	i := d.i
+	d.i++
+	if d.i > len(d.in) {
+		corrupted()
+	}
+	return d.in[i]
+}
+
+func (d *decoder) readBytes(length int32) []byte {
+	if length < 0 {
+		corrupted()
+	}
+	start := d.i
+	d.i += int(length)
+	if d.i < start || d.i > len(d.in) {
+		corrupted()
+	}
+	return d.in[start : start+int(length)]
+}
diff --git a/go/vendor/github.com/globalsign/mgo/bson/encode.go b/go/vendor/github.com/globalsign/mgo/bson/encode.go
new file mode 100644
index 0000000..d0c6b2a
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/encode.go
@@ -0,0 +1,645 @@
+// BSON library for Go
+//
+// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// gobson - BSON library for Go.
+
+package bson
+
+import (
+	"encoding/json"
+	"fmt"
+	"math"
+	"net/url"
+	"reflect"
+	"sort"
+	"strconv"
+	"sync"
+	"time"
+)
+
+// --------------------------------------------------------------------------
+// Some internal infrastructure.
+
+var (
+	typeBinary         = reflect.TypeOf(Binary{})
+	typeObjectId       = reflect.TypeOf(ObjectId(""))
+	typeDBPointer      = reflect.TypeOf(DBPointer{"", ObjectId("")})
+	typeSymbol         = reflect.TypeOf(Symbol(""))
+	typeMongoTimestamp = reflect.TypeOf(MongoTimestamp(0))
+	typeOrderKey       = reflect.TypeOf(MinKey)
+	typeDocElem        = reflect.TypeOf(DocElem{})
+	typeRawDocElem     = reflect.TypeOf(RawDocElem{})
+	typeRaw            = reflect.TypeOf(Raw{})
+	typeRawPtr         = reflect.PtrTo(reflect.TypeOf(Raw{}))
+	typeURL            = reflect.TypeOf(url.URL{})
+	typeTime           = reflect.TypeOf(time.Time{})
+	typeString         = reflect.TypeOf("")
+	typeJSONNumber     = reflect.TypeOf(json.Number(""))
+	typeTimeDuration   = reflect.TypeOf(time.Duration(0))
+)
+
+var (
+	// spec for []uint8 or []byte encoding
+	arrayOps = map[string]bool{
+		"$in":  true,
+		"$nin": true,
+		"$all": true,
+	}
+)
+
+const itoaCacheSize = 32
+
+const (
+	getterUnknown = iota
+	getterNone
+	getterTypeVal
+	getterTypePtr
+	getterAddr
+)
+
+var itoaCache []string
+
+var getterStyles map[reflect.Type]int
+var getterIface reflect.Type
+var getterMutex sync.RWMutex
+
+func init() {
+	itoaCache = make([]string, itoaCacheSize)
+	for i := 0; i != itoaCacheSize; i++ {
+		itoaCache[i] = strconv.Itoa(i)
+	}
+	var iface Getter
+	getterIface = reflect.TypeOf(&iface).Elem()
+	getterStyles = make(map[reflect.Type]int)
+}
+
+func itoa(i int) string {
+	if i < itoaCacheSize {
+		return itoaCache[i]
+	}
+	return strconv.Itoa(i)
+}
+
+func getterStyle(outt reflect.Type) int {
+	getterMutex.RLock()
+	style := getterStyles[outt]
+	getterMutex.RUnlock()
+	if style != getterUnknown {
+		return style
+	}
+
+	getterMutex.Lock()
+	defer getterMutex.Unlock()
+	if outt.Implements(getterIface) {
+		vt := outt
+		for vt.Kind() == reflect.Ptr {
+			vt = vt.Elem()
+		}
+		if vt.Implements(getterIface) {
+			style = getterTypeVal
+		} else {
+			style = getterTypePtr
+		}
+	} else if reflect.PtrTo(outt).Implements(getterIface) {
+		style = getterAddr
+	} else {
+		style = getterNone
+	}
+	getterStyles[outt] = style
+	return style
+}
+
+func getGetter(outt reflect.Type, out reflect.Value) Getter {
+	style := getterStyle(outt)
+	if style == getterNone {
+		return nil
+	}
+	if style == getterAddr {
+		if !out.CanAddr() {
+			return nil
+		}
+		return out.Addr().Interface().(Getter)
+	}
+	if style == getterTypeVal && out.Kind() == reflect.Ptr && out.IsNil() {
+		return nil
+	}
+	return out.Interface().(Getter)
+}
+
+// --------------------------------------------------------------------------
+// Marshaling of the document value itself.
+
+type encoder struct {
+	out []byte
+}
+
+func (e *encoder) addDoc(v reflect.Value) {
+	for {
+		if vi, ok := v.Interface().(Getter); ok {
+			getv, err := vi.GetBSON()
+			if err != nil {
+				panic(err)
+			}
+			v = reflect.ValueOf(getv)
+			continue
+		}
+		if v.Kind() == reflect.Ptr {
+			v = v.Elem()
+			continue
+		}
+		break
+	}
+
+	if v.Type() == typeRaw {
+		raw := v.Interface().(Raw)
+		if raw.Kind != 0x03 && raw.Kind != 0x00 {
+			panic("Attempted to marshal Raw kind " + strconv.Itoa(int(raw.Kind)) + " as a document")
+		}
+		if len(raw.Data) == 0 {
+			panic("Attempted to marshal empty Raw document")
+		}
+		e.addBytes(raw.Data...)
+		return
+	}
+
+	start := e.reserveInt32()
+
+	switch v.Kind() {
+	case reflect.Map:
+		e.addMap(v)
+	case reflect.Struct:
+		e.addStruct(v)
+	case reflect.Array, reflect.Slice:
+		e.addSlice(v)
+	default:
+		panic("Can't marshal " + v.Type().String() + " as a BSON document")
+	}
+
+	e.addBytes(0)
+	e.setInt32(start, int32(len(e.out)-start))
+}
+
+func (e *encoder) addMap(v reflect.Value) {
+	for _, k := range v.MapKeys() {
+		e.addElem(fmt.Sprint(k), v.MapIndex(k), false)
+	}
+}
+
+func (e *encoder) addStruct(v reflect.Value) {
+	sinfo, err := getStructInfo(v.Type())
+	if err != nil {
+		panic(err)
+	}
+	var value reflect.Value
+	if sinfo.InlineMap >= 0 {
+		m := v.Field(sinfo.InlineMap)
+		if m.Len() > 0 {
+			for _, k := range m.MapKeys() {
+				ks := k.String()
+				if _, found := sinfo.FieldsMap[ks]; found {
+					panic(fmt.Sprintf("Can't have key %q in inlined map; conflicts with struct field", ks))
+				}
+				e.addElem(ks, m.MapIndex(k), false)
+			}
+		}
+	}
+	for _, info := range sinfo.FieldsList {
+		if info.Inline == nil {
+			value = v.Field(info.Num)
+		} else {
+			// as pointers to struct are allowed here,
+			// there is no guarantee that pointer won't be nil.
+			//
+			// It is expected allowed behaviour
+			// so info.Inline MAY consist index to a nil pointer
+			// and that is why we safely call v.FieldByIndex and just continue on panic
+			field, errField := safeFieldByIndex(v, info.Inline)
+			if errField != nil {
+				continue
+			}
+
+			value = field
+		}
+		if info.OmitEmpty && isZero(value) {
+			continue
+		}
+		if useRespectNilValues &&
+			(value.Kind() == reflect.Slice || value.Kind() == reflect.Map) &&
+			value.IsNil() {
+			e.addElem(info.Key, reflect.ValueOf(nil), info.MinSize)
+			continue
+		}
+		e.addElem(info.Key, value, info.MinSize)
+	}
+}
+
+func safeFieldByIndex(v reflect.Value, index []int) (result reflect.Value, err error) {
+	defer func() {
+		if recovered := recover(); recovered != nil {
+			switch r := recovered.(type) {
+			case string:
+				err = fmt.Errorf("%s", r)
+			case error:
+				err = r
+			}
+		}
+	}()
+
+	result = v.FieldByIndex(index)
+	return
+}
+
+func isZero(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.String:
+		return len(v.String()) == 0
+	case reflect.Ptr, reflect.Interface:
+		return v.IsNil()
+	case reflect.Slice:
+		return v.Len() == 0
+	case reflect.Map:
+		return v.Len() == 0
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return v.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Struct:
+		vt := v.Type()
+		if vt == typeTime {
+			return v.Interface().(time.Time).IsZero()
+		}
+		for i := 0; i < v.NumField(); i++ {
+			if vt.Field(i).PkgPath != "" && !vt.Field(i).Anonymous {
+				continue // Private field
+			}
+			if !isZero(v.Field(i)) {
+				return false
+			}
+		}
+		return true
+	}
+	return false
+}
+
+func (e *encoder) addSlice(v reflect.Value) {
+	vi := v.Interface()
+	if d, ok := vi.(D); ok {
+		for _, elem := range d {
+			e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
+		}
+		return
+	}
+	if d, ok := vi.(RawD); ok {
+		for _, elem := range d {
+			e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
+		}
+		return
+	}
+	l := v.Len()
+	et := v.Type().Elem()
+	if et == typeDocElem {
+		for i := 0; i < l; i++ {
+			elem := v.Index(i).Interface().(DocElem)
+			e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
+		}
+		return
+	}
+	if et == typeRawDocElem {
+		for i := 0; i < l; i++ {
+			elem := v.Index(i).Interface().(RawDocElem)
+			e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
+		}
+		return
+	}
+	for i := 0; i < l; i++ {
+		e.addElem(itoa(i), v.Index(i), false)
+	}
+}
+
+// --------------------------------------------------------------------------
+// Marshaling of elements in a document.
+
+func (e *encoder) addElemName(kind byte, name string) {
+	e.addBytes(kind)
+	e.addBytes([]byte(name)...)
+	e.addBytes(0)
+}
+
+func (e *encoder) addElem(name string, v reflect.Value, minSize bool) {
+
+	if !v.IsValid() {
+		e.addElemName(0x0A, name)
+		return
+	}
+
+	if getter := getGetter(v.Type(), v); getter != nil {
+		getv, err := getter.GetBSON()
+		if err != nil {
+			panic(err)
+		}
+		e.addElem(name, reflect.ValueOf(getv), minSize)
+		return
+	}
+
+	switch v.Kind() {
+
+	case reflect.Interface:
+		e.addElem(name, v.Elem(), minSize)
+
+	case reflect.Ptr:
+		e.addElem(name, v.Elem(), minSize)
+
+	case reflect.String:
+		s := v.String()
+		switch v.Type() {
+		case typeObjectId:
+			if len(s) != 12 {
+				panic("ObjectIDs must be exactly 12 bytes long (got " +
+					strconv.Itoa(len(s)) + ")")
+			}
+			e.addElemName(0x07, name)
+			e.addBytes([]byte(s)...)
+		case typeSymbol:
+			e.addElemName(0x0E, name)
+			e.addStr(s)
+		case typeJSONNumber:
+			n := v.Interface().(json.Number)
+			if i, err := n.Int64(); err == nil {
+				e.addElemName(0x12, name)
+				e.addInt64(i)
+			} else if f, err := n.Float64(); err == nil {
+				e.addElemName(0x01, name)
+				e.addFloat64(f)
+			} else {
+				panic("failed to convert json.Number to a number: " + s)
+			}
+		default:
+			e.addElemName(0x02, name)
+			e.addStr(s)
+		}
+
+	case reflect.Float32, reflect.Float64:
+		e.addElemName(0x01, name)
+		e.addFloat64(v.Float())
+
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		u := v.Uint()
+		if int64(u) < 0 {
+			panic("BSON has no uint64 type, and value is too large to fit correctly in an int64")
+		} else if u <= math.MaxInt32 && (minSize || v.Kind() <= reflect.Uint32) {
+			e.addElemName(0x10, name)
+			e.addInt32(int32(u))
+		} else {
+			e.addElemName(0x12, name)
+			e.addInt64(int64(u))
+		}
+
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		switch v.Type() {
+		case typeMongoTimestamp:
+			e.addElemName(0x11, name)
+			e.addInt64(v.Int())
+
+		case typeOrderKey:
+			if v.Int() == int64(MaxKey) {
+				e.addElemName(0x7F, name)
+			} else {
+				e.addElemName(0xFF, name)
+			}
+		case typeTimeDuration:
+			// Stored as int64
+			e.addElemName(0x12, name)
+
+			e.addInt64(int64(v.Int() / 1e6))
+		default:
+			i := v.Int()
+			if (minSize || v.Type().Kind() != reflect.Int64) && i >= math.MinInt32 && i <= math.MaxInt32 {
+				// It fits into an int32, encode as such.
+				e.addElemName(0x10, name)
+				e.addInt32(int32(i))
+			} else {
+				e.addElemName(0x12, name)
+				e.addInt64(i)
+			}
+		}
+
+	case reflect.Bool:
+		e.addElemName(0x08, name)
+		if v.Bool() {
+			e.addBytes(1)
+		} else {
+			e.addBytes(0)
+		}
+
+	case reflect.Map:
+		e.addElemName(0x03, name)
+		e.addDoc(v)
+
+	case reflect.Slice:
+		vt := v.Type()
+		et := vt.Elem()
+		if et.Kind() == reflect.Uint8 {
+			if arrayOps[name] {
+				e.addElemName(0x04, name)
+				e.addDoc(v)
+			} else {
+				e.addElemName(0x05, name)
+				e.addBinary(0x00, v.Bytes())
+			}
+		} else if et == typeDocElem || et == typeRawDocElem {
+			e.addElemName(0x03, name)
+			e.addDoc(v)
+		} else {
+			e.addElemName(0x04, name)
+			e.addDoc(v)
+		}
+
+	case reflect.Array:
+		et := v.Type().Elem()
+		if et.Kind() == reflect.Uint8 {
+			if arrayOps[name] {
+				e.addElemName(0x04, name)
+				e.addDoc(v)
+			} else {
+				e.addElemName(0x05, name)
+				if v.CanAddr() {
+					e.addBinary(0x00, v.Slice(0, v.Len()).Interface().([]byte))
+				} else {
+					n := v.Len()
+					e.addInt32(int32(n))
+					e.addBytes(0x00)
+					for i := 0; i < n; i++ {
+						el := v.Index(i)
+						e.addBytes(byte(el.Uint()))
+					}
+				}
+			}
+		} else {
+			e.addElemName(0x04, name)
+			e.addDoc(v)
+		}
+
+	case reflect.Struct:
+		switch s := v.Interface().(type) {
+
+		case Raw:
+			kind := s.Kind
+			if kind == 0x00 {
+				kind = 0x03
+			}
+			if len(s.Data) == 0 && kind != 0x06 && kind != 0x0A && kind != 0xFF && kind != 0x7F {
+				panic("Attempted to marshal empty Raw document")
+			}
+			e.addElemName(kind, name)
+			e.addBytes(s.Data...)
+
+		case Binary:
+			e.addElemName(0x05, name)
+			e.addBinary(s.Kind, s.Data)
+
+		case Decimal128:
+			e.addElemName(0x13, name)
+			e.addInt64(int64(s.l))
+			e.addInt64(int64(s.h))
+
+		case DBPointer:
+			e.addElemName(0x0C, name)
+			e.addStr(s.Namespace)
+			if len(s.Id) != 12 {
+				panic("ObjectIDs must be exactly 12 bytes long (got " +
+					strconv.Itoa(len(s.Id)) + ")")
+			}
+			e.addBytes([]byte(s.Id)...)
+
+		case RegEx:
+			e.addElemName(0x0B, name)
+			e.addCStr(s.Pattern)
+			options := runes(s.Options)
+			sort.Sort(options)
+			e.addCStr(string(options))
+
+		case JavaScript:
+			if s.Scope == nil {
+				e.addElemName(0x0D, name)
+				e.addStr(s.Code)
+			} else {
+				e.addElemName(0x0F, name)
+				start := e.reserveInt32()
+				e.addStr(s.Code)
+				e.addDoc(reflect.ValueOf(s.Scope))
+				e.setInt32(start, int32(len(e.out)-start))
+			}
+
+		case time.Time:
+			// MongoDB handles timestamps as milliseconds.
+			e.addElemName(0x09, name)
+			e.addInt64(s.Unix()*1000 + int64(s.Nanosecond()/1e6))
+
+		case url.URL:
+			e.addElemName(0x02, name)
+			e.addStr(s.String())
+
+		case undefined:
+			e.addElemName(0x06, name)
+
+		default:
+			e.addElemName(0x03, name)
+			e.addDoc(v)
+		}
+
+	default:
+		panic("Can't marshal " + v.Type().String() + " in a BSON document")
+	}
+}
+
+// -------------
+// Helper method for sorting regex options
+type runes []rune
+
+func (a runes) Len() int           { return len(a) }
+func (a runes) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a runes) Less(i, j int) bool { return a[i] < a[j] }
+
+// --------------------------------------------------------------------------
+// Marshaling of base types.
+
+func (e *encoder) addBinary(subtype byte, v []byte) {
+	if subtype == 0x02 {
+		// Wonder how that brilliant idea came to life. Obsolete, luckily.
+		e.addInt32(int32(len(v) + 4))
+		e.addBytes(subtype)
+		e.addInt32(int32(len(v)))
+	} else {
+		e.addInt32(int32(len(v)))
+		e.addBytes(subtype)
+	}
+	e.addBytes(v...)
+}
+
+func (e *encoder) addStr(v string) {
+	e.addInt32(int32(len(v) + 1))
+	e.addCStr(v)
+}
+
+func (e *encoder) addCStr(v string) {
+	e.addBytes([]byte(v)...)
+	e.addBytes(0)
+}
+
+func (e *encoder) reserveInt32() (pos int) {
+	pos = len(e.out)
+	e.addBytes(0, 0, 0, 0)
+	return pos
+}
+
+func (e *encoder) setInt32(pos int, v int32) {
+	e.out[pos+0] = byte(v)
+	e.out[pos+1] = byte(v >> 8)
+	e.out[pos+2] = byte(v >> 16)
+	e.out[pos+3] = byte(v >> 24)
+}
+
+func (e *encoder) addInt32(v int32) {
+	u := uint32(v)
+	e.addBytes(byte(u), byte(u>>8), byte(u>>16), byte(u>>24))
+}
+
+func (e *encoder) addInt64(v int64) {
+	u := uint64(v)
+	e.addBytes(byte(u), byte(u>>8), byte(u>>16), byte(u>>24),
+		byte(u>>32), byte(u>>40), byte(u>>48), byte(u>>56))
+}
+
+func (e *encoder) addFloat64(v float64) {
+	e.addInt64(int64(math.Float64bits(v)))
+}
+
+func (e *encoder) addBytes(v ...byte) {
+	e.out = append(e.out, v...)
+}
diff --git a/go/vendor/github.com/globalsign/mgo/bson/json.go b/go/vendor/github.com/globalsign/mgo/bson/json.go
new file mode 100644
index 0000000..045c713
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/json.go
@@ -0,0 +1,384 @@
+package bson
+
+import (
+	"bytes"
+	"encoding/base64"
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/globalsign/mgo/internal/json"
+)
+
+// UnmarshalJSON unmarshals a JSON value that may hold non-standard
+// syntax as defined in BSON's extended JSON specification.
+func UnmarshalJSON(data []byte, value interface{}) error {
+	d := json.NewDecoder(bytes.NewBuffer(data))
+	d.Extend(&jsonExt)
+	return d.Decode(value)
+}
+
+// MarshalJSON marshals a JSON value that may hold non-standard
+// syntax as defined in BSON's extended JSON specification.
+func MarshalJSON(value interface{}) ([]byte, error) {
+	var buf bytes.Buffer
+	e := json.NewEncoder(&buf)
+	e.Extend(&jsonExt)
+	err := e.Encode(value)
+	if err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// jdec is used internally by the JSON decoding functions
+// so they may unmarshal functions without getting into endless
+// recursion due to keyed objects.
+func jdec(data []byte, value interface{}) error {
+	d := json.NewDecoder(bytes.NewBuffer(data))
+	d.Extend(&funcExt)
+	return d.Decode(value)
+}
+
+var jsonExt json.Extension
+var funcExt json.Extension
+
+// TODO
+// - Shell regular expressions ("/regexp/opts")
+
+func init() {
+	jsonExt.DecodeUnquotedKeys(true)
+	jsonExt.DecodeTrailingCommas(true)
+
+	funcExt.DecodeFunc("BinData", "$binaryFunc", "$type", "$binary")
+	jsonExt.DecodeKeyed("$binary", jdecBinary)
+	jsonExt.DecodeKeyed("$binaryFunc", jdecBinary)
+	jsonExt.EncodeType([]byte(nil), jencBinarySlice)
+	jsonExt.EncodeType(Binary{}, jencBinaryType)
+
+	funcExt.DecodeFunc("ISODate", "$dateFunc", "S")
+	funcExt.DecodeFunc("new Date", "$dateFunc", "S")
+	jsonExt.DecodeKeyed("$date", jdecDate)
+	jsonExt.DecodeKeyed("$dateFunc", jdecDate)
+	jsonExt.EncodeType(time.Time{}, jencDate)
+
+	funcExt.DecodeFunc("Timestamp", "$timestamp", "t", "i")
+	jsonExt.DecodeKeyed("$timestamp", jdecTimestamp)
+	jsonExt.EncodeType(MongoTimestamp(0), jencTimestamp)
+
+	funcExt.DecodeConst("undefined", Undefined)
+
+	jsonExt.DecodeKeyed("$regex", jdecRegEx)
+	jsonExt.EncodeType(RegEx{}, jencRegEx)
+
+	funcExt.DecodeFunc("ObjectId", "$oidFunc", "Id")
+	jsonExt.DecodeKeyed("$oid", jdecObjectId)
+	jsonExt.DecodeKeyed("$oidFunc", jdecObjectId)
+	jsonExt.EncodeType(ObjectId(""), jencObjectId)
+
+	funcExt.DecodeFunc("DBRef", "$dbrefFunc", "$ref", "$id")
+	jsonExt.DecodeKeyed("$dbrefFunc", jdecDBRef)
+
+	funcExt.DecodeFunc("NumberLong", "$numberLongFunc", "N")
+	jsonExt.DecodeKeyed("$numberLong", jdecNumberLong)
+	jsonExt.DecodeKeyed("$numberLongFunc", jdecNumberLong)
+	jsonExt.EncodeType(int64(0), jencNumberLong)
+	jsonExt.EncodeType(int(0), jencInt)
+
+	funcExt.DecodeConst("MinKey", MinKey)
+	funcExt.DecodeConst("MaxKey", MaxKey)
+	jsonExt.DecodeKeyed("$minKey", jdecMinKey)
+	jsonExt.DecodeKeyed("$maxKey", jdecMaxKey)
+	jsonExt.EncodeType(orderKey(0), jencMinMaxKey)
+
+	jsonExt.DecodeKeyed("$undefined", jdecUndefined)
+	jsonExt.EncodeType(Undefined, jencUndefined)
+
+	jsonExt.Extend(&funcExt)
+}
+
+func fbytes(format string, args ...interface{}) []byte {
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, format, args...)
+	return buf.Bytes()
+}
+
+func jdecBinary(data []byte) (interface{}, error) {
+	var v struct {
+		Binary []byte `json:"$binary"`
+		Type   string `json:"$type"`
+		Func   struct {
+			Binary []byte `json:"$binary"`
+			Type   int64  `json:"$type"`
+		} `json:"$binaryFunc"`
+	}
+	err := jdec(data, &v)
+	if err != nil {
+		return nil, err
+	}
+
+	var binData []byte
+	var binKind int64
+	if v.Type == "" && v.Binary == nil {
+		binData = v.Func.Binary
+		binKind = v.Func.Type
+	} else if v.Type == "" {
+		return v.Binary, nil
+	} else {
+		binData = v.Binary
+		binKind, err = strconv.ParseInt(v.Type, 0, 64)
+		if err != nil {
+			binKind = -1
+		}
+	}
+
+	if binKind == 0 {
+		return binData, nil
+	}
+	if binKind < 0 || binKind > 255 {
+		return nil, fmt.Errorf("invalid type in binary object: %s", data)
+	}
+
+	return Binary{Kind: byte(binKind), Data: binData}, nil
+}
+
+func jencBinarySlice(v interface{}) ([]byte, error) {
+	in := v.([]byte)
+	out := make([]byte, base64.StdEncoding.EncodedLen(len(in)))
+	base64.StdEncoding.Encode(out, in)
+	return fbytes(`{"$binary":"%s","$type":"0x0"}`, out), nil
+}
+
+func jencBinaryType(v interface{}) ([]byte, error) {
+	in := v.(Binary)
+	out := make([]byte, base64.StdEncoding.EncodedLen(len(in.Data)))
+	base64.StdEncoding.Encode(out, in.Data)
+	return fbytes(`{"$binary":"%s","$type":"0x%x"}`, out, in.Kind), nil
+}
+
+const jdateFormat = "2006-01-02T15:04:05.999Z07:00"
+
+func jdecDate(data []byte) (interface{}, error) {
+	var v struct {
+		S    string `json:"$date"`
+		Func struct {
+			S string
+		} `json:"$dateFunc"`
+	}
+	_ = jdec(data, &v)
+	if v.S == "" {
+		v.S = v.Func.S
+	}
+	if v.S != "" {
+		var errs []string
+		for _, format := range []string{jdateFormat, "2006-01-02"} {
+			t, err := time.Parse(format, v.S)
+			if err == nil {
+				return t, nil
+			}
+			errs = append(errs, err.Error())
+		}
+		return nil, fmt.Errorf("cannot parse date: %q [%s]", v.S, strings.Join(errs, ", "))
+	}
+
+	var vn struct {
+		Date struct {
+			N int64 `json:"$numberLong,string"`
+		} `json:"$date"`
+		Func struct {
+			S int64
+		} `json:"$dateFunc"`
+	}
+	err := jdec(data, &vn)
+	if err != nil {
+		return nil, fmt.Errorf("cannot parse date: %q", data)
+	}
+	n := vn.Date.N
+	if n == 0 {
+		n = vn.Func.S
+	}
+	return time.Unix(n/1000, n%1000*1e6).UTC(), nil
+}
+
+func jencDate(v interface{}) ([]byte, error) {
+	t := v.(time.Time)
+	return fbytes(`{"$date":%q}`, t.Format(jdateFormat)), nil
+}
+
+func jdecTimestamp(data []byte) (interface{}, error) {
+	var v struct {
+		Func struct {
+			T int32 `json:"t"`
+			I int32 `json:"i"`
+		} `json:"$timestamp"`
+	}
+	err := jdec(data, &v)
+	if err != nil {
+		return nil, err
+	}
+	return MongoTimestamp(uint64(v.Func.T)<<32 | uint64(uint32(v.Func.I))), nil
+}
+
+func jencTimestamp(v interface{}) ([]byte, error) {
+	ts := uint64(v.(MongoTimestamp))
+	return fbytes(`{"$timestamp":{"t":%d,"i":%d}}`, ts>>32, uint32(ts)), nil
+}
+
+func jdecRegEx(data []byte) (interface{}, error) {
+	var v struct {
+		Regex   string `json:"$regex"`
+		Options string `json:"$options"`
+	}
+	err := jdec(data, &v)
+	if err != nil {
+		return nil, err
+	}
+	return RegEx{v.Regex, v.Options}, nil
+}
+
+func jencRegEx(v interface{}) ([]byte, error) {
+	re := v.(RegEx)
+	type regex struct {
+		Regex   string `json:"$regex"`
+		Options string `json:"$options"`
+	}
+	return json.Marshal(regex{re.Pattern, re.Options})
+}
+
+func jdecObjectId(data []byte) (interface{}, error) {
+	var v struct {
+		Id   string `json:"$oid"`
+		Func struct {
+			Id string
+		} `json:"$oidFunc"`
+	}
+	err := jdec(data, &v)
+	if err != nil {
+		return nil, err
+	}
+	if v.Id == "" {
+		v.Id = v.Func.Id
+	}
+	return ObjectIdHex(v.Id), nil
+}
+
+func jencObjectId(v interface{}) ([]byte, error) {
+	return fbytes(`{"$oid":"%s"}`, v.(ObjectId).Hex()), nil
+}
+
+func jdecDBRef(data []byte) (interface{}, error) {
+	// TODO Support unmarshaling $ref and $id into the input value.
+	var v struct {
+		Obj map[string]interface{} `json:"$dbrefFunc"`
+	}
+	// TODO Fix this. Must not be required.
+	v.Obj = make(map[string]interface{})
+	err := jdec(data, &v)
+	if err != nil {
+		return nil, err
+	}
+	return v.Obj, nil
+}
+
+func jdecNumberLong(data []byte) (interface{}, error) {
+	var v struct {
+		N    int64 `json:"$numberLong,string"`
+		Func struct {
+			N int64 `json:",string"`
+		} `json:"$numberLongFunc"`
+	}
+	var vn struct {
+		N    int64 `json:"$numberLong"`
+		Func struct {
+			N int64
+		} `json:"$numberLongFunc"`
+	}
+	err := jdec(data, &v)
+	if err != nil {
+		err = jdec(data, &vn)
+		v.N = vn.N
+		v.Func.N = vn.Func.N
+	}
+	if err != nil {
+		return nil, err
+	}
+	if v.N != 0 {
+		return v.N, nil
+	}
+	return v.Func.N, nil
+}
+
+func jencNumberLong(v interface{}) ([]byte, error) {
+	n := v.(int64)
+	f := `{"$numberLong":"%d"}`
+	if n <= 1<<53 {
+		f = `{"$numberLong":%d}`
+	}
+	return fbytes(f, n), nil
+}
+
+func jencInt(v interface{}) ([]byte, error) {
+	n := v.(int)
+	f := `{"$numberLong":"%d"}`
+	if int64(n) <= 1<<53 {
+		f = `%d`
+	}
+	return fbytes(f, n), nil
+}
+
+func jdecMinKey(data []byte) (interface{}, error) {
+	var v struct {
+		N int64 `json:"$minKey"`
+	}
+	err := jdec(data, &v)
+	if err != nil {
+		return nil, err
+	}
+	if v.N != 1 {
+		return nil, fmt.Errorf("invalid $minKey object: %s", data)
+	}
+	return MinKey, nil
+}
+
+func jdecMaxKey(data []byte) (interface{}, error) {
+	var v struct {
+		N int64 `json:"$maxKey"`
+	}
+	err := jdec(data, &v)
+	if err != nil {
+		return nil, err
+	}
+	if v.N != 1 {
+		return nil, fmt.Errorf("invalid $maxKey object: %s", data)
+	}
+	return MaxKey, nil
+}
+
+func jencMinMaxKey(v interface{}) ([]byte, error) {
+	switch v.(orderKey) {
+	case MinKey:
+		return []byte(`{"$minKey":1}`), nil
+	case MaxKey:
+		return []byte(`{"$maxKey":1}`), nil
+	}
+	panic(fmt.Sprintf("invalid $minKey/$maxKey value: %d", v))
+}
+
+func jdecUndefined(data []byte) (interface{}, error) {
+	var v struct {
+		B bool `json:"$undefined"`
+	}
+	err := jdec(data, &v)
+	if err != nil {
+		return nil, err
+	}
+	if !v.B {
+		return nil, fmt.Errorf("invalid $undefined object: %s", data)
+	}
+	return Undefined, nil
+}
+
+func jencUndefined(v interface{}) ([]byte, error) {
+	return []byte(`{"$undefined":true}`), nil
+}
diff --git a/go/vendor/github.com/globalsign/mgo/bson/stream.go b/go/vendor/github.com/globalsign/mgo/bson/stream.go
new file mode 100644
index 0000000..4665284
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/stream.go
@@ -0,0 +1,90 @@
+package bson
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+const (
+	// MinDocumentSize is the size of the smallest possible valid BSON document:
+	// an int32 size header + 0x00 (end of document).
+	MinDocumentSize = 5
+
+	// MaxDocumentSize is the largest possible size for a BSON document allowed by MongoDB,
+	// that is, 16 MiB (see https://docs.mongodb.com/manual/reference/limits/).
+	MaxDocumentSize = 16777216
+)
+
+// ErrInvalidDocumentSize is an error returned when a BSON document's header
+// contains a size smaller than MinDocumentSize or greater than MaxDocumentSize.
+type ErrInvalidDocumentSize struct {
+	DocumentSize int32
+}
+
+func (e ErrInvalidDocumentSize) Error() string {
+	return fmt.Sprintf("invalid document size %d", e.DocumentSize)
+}
+
+// A Decoder reads and decodes BSON values from an input stream.
+type Decoder struct {
+	source io.Reader
+}
+
+// NewDecoder returns a new Decoder that reads from source.
+// It does not add any extra buffering, and may not read data from source beyond the BSON values requested.
+func NewDecoder(source io.Reader) *Decoder {
+	return &Decoder{source: source}
+}
+
+// Decode reads the next BSON-encoded value from its input and stores it in the value pointed to by v.
+// See the documentation for Unmarshal for details about the conversion of BSON into a Go value.
+func (dec *Decoder) Decode(v interface{}) (err error) {
+	// BSON documents start with their size as a *signed* int32.
+	var docSize int32
+	if err = binary.Read(dec.source, binary.LittleEndian, &docSize); err != nil {
+		return
+	}
+
+	if docSize < MinDocumentSize || docSize > MaxDocumentSize {
+		return ErrInvalidDocumentSize{DocumentSize: docSize}
+	}
+
+	docBuffer := bytes.NewBuffer(make([]byte, 0, docSize))
+	if err = binary.Write(docBuffer, binary.LittleEndian, docSize); err != nil {
+		return
+	}
+
+	// docSize is the *full* document's size (including the 4-byte size header,
+	// which has already been read).
+	if _, err = io.CopyN(docBuffer, dec.source, int64(docSize-4)); err != nil {
+		return
+	}
+
+	// Let Unmarshal handle the rest.
+	defer handleErr(&err)
+	return Unmarshal(docBuffer.Bytes(), v)
+}
+
+// An Encoder encodes and writes BSON values to an output stream.
+type Encoder struct {
+	target io.Writer
+}
+
+// NewEncoder returns a new Encoder that writes to target.
+func NewEncoder(target io.Writer) *Encoder {
+	return &Encoder{target: target}
+}
+
+// Encode encodes v to BSON, and if successful writes it to the Encoder's output stream.
+// See the documentation for Marshal for details about the conversion of Go values to BSON.
+func (enc *Encoder) Encode(v interface{}) error {
+	data, err := Marshal(v)
+	if err != nil {
+		return err
+	}
+
+	_, err = enc.target.Write(data)
+	return err
+}