*: rejigger tls certs and more

This pretty large change does the following:

 - moves nix from bootstrap.hswaw.net to nix/
 - changes clustercfg to use cfssl and moves it to cluster/clustercfg
 - changes clustercfg to source information about target location of
   certs from nix
 - changes clustercfg to push nix config
 - changes tls certs to have more than one CA
 - recalculates all TLS certs
   (it keeps the old serviceaccoutns key, otherwise we end up with
   invalid serviceaccounts - the cert doesn't match, but who cares,
   it's not used anyway)
diff --git a/tools/install.sh b/tools/install.sh
index 82713a2..6a9bec1 100755
--- a/tools/install.sh
+++ b/tools/install.sh
@@ -8,5 +8,5 @@
 cd "${hscloud_root}"
 
 bazel build \
-        //tools:kubectl //tools:kubecfg //tools:clustercfg //tools:secretstore \
+        //tools:kubectl //tools:kubecfg //tools:secretstore \
         //tools:pass //tools:calicoctl.bin