etcd v0.5.0-alpha.1

- add etcdctl member {list,add,remove} see https://github.com/coreos/etcd/blob/master/Documentation/0.5/runtime-configuration.md
- add `etcdctl ls -p` to to emulate `ls -p`
- attach cluster ID in http headers for client response
- cleanup the logging of member IDs
- cleanup the logging of member removal
- bump the server timeout for requests to a more reasonable value
- move /v2/admin/members to /v2/members
- test cases added that matches 1-to-1 to consistency considerations in the raft paper
- add admin guide. See https://github.com/coreos/etcd/blob/master/Documentation/0.5/admin_guide.md
- remove etcdctl weak consistency to the exec-watch

Thank you to: Yicheng Qin, Xiang Li, Micah Hausler, Pierre Phaneuf, Kelsey Hightower, Jonathan Boulle, Brian “BC” Waldon, Brian Ketelsen, Brandon Philips