coreos/etcd — pull request #1426 by xiangli-cmu (2014-10-27 14:55:51+00:00)
Title: etcdhttp: attach clusterID to key and adminMember endpoint

solves #1225

I guess we need to clean up the handler functions a little bit after this.
We have a few common logic shared with http handlers now:
1. check code allowance
2. attach cluster id

We can have a function to wrapper these logic to other handlers and return new wrapped handling function. So we can consolidate the shared logic.