etcdserver: etcdserver generates the ID when adding new member.
When adding new member, the etcdserver generates the ID based on the current time
and the given peerurls. We include time to add the uniqueness, since the node with
same peerurls should be able to (add, then remove) several times.
main: fix default case
Merge pull request #1352 from coreos/fix_main

main: fix default case
etcdhttp: test bad url for POST on admin endopint
Merge pull request #1347 from coreos/gen_nodeID

etcdserver: etcdserver generates the ID when adding new member.
main: use our own flagset in setupCluster
Merge pull request #1356 from coreos/fix_dis

main: use our own flagset in setupCluster
etcdserver: Check the initial cluster settings after checking if the WAL exists
etcdserver: cleanup the cluster ID error message

1) Don't panic since we know exactly where this is coming from and don't
need the user to see a full back trace

2) Add docs explaining this situation a bit further

3) Cleanup the error to look like other similiar errors
Merge pull request #1355 from barakmich/cluster_after_wal

etcdserver: Check the initial cluster settings after checking if the WAL...
Merge pull request #1358 from philips/etcdserver-cleanup-cluster-id-msg

etcdserver: cleanup the cluster ID error message
etcdserver: fixup mismatch error line

Both wcid and gcid are strings, don't try to print it out in hex.
Merge pull request #1359 from philips/fix-mismatch-error

etcdserver: fixup mismatch error line
etcdserver: admin endpoint accepts json body
etcdserver: use hex for cluster and machine id

Continue using hex everywhere. Including here.

TODO: cleanup the printing of the structs which currently have decimal
to/from:

`{Type:MsgAppResp To:9973738105406047488 From:17050684879817348455 T...`
Merge pull request #1357 from coreos/accept_json

etcdserver: admin endpoint accepts json body
etcdserver: admin PUT returns the json representation of the newly created member
Merge pull request #1362 from philips/consistent-hex-use

etcdserver: use hex for cluster and machine id
Merge pull request #1363 from coreos/return_json

etcdserver: admin PUT returns the json representation of the newly creat...
etcdserver: refactor cluster and clusterStore

Integrate clusterStore into cluster, and let cluster become the source of
cluster info.