app/gerrit: import OAuth provider and add SSO support

This change:

 - imports gerrit-oauth-provider from upstream
 - adds sso.hackerspae.pl support to it

Change-Id: I92e7053614a9297bf1ced3aac044c0002acd836a
diff --git a/app/gerrit/gerrit-oauth-provider/.gitignore b/app/gerrit/gerrit-oauth-provider/.gitignore
new file mode 100644
index 0000000..445b95a
--- /dev/null
+++ b/app/gerrit/gerrit-oauth-provider/.gitignore
@@ -0,0 +1,11 @@
+/.classpath
+/.project
+/.settings
+/bazel-bin
+/bazel-genfiles
+/bazel-gerrit-oauth-provider
+/bazel-out
+/bazel-testlogs
+/eclipse-out
+/.idea
+*.swp