etcdserver/etcdhttp: split out peers and add tests
raft: test node step
etcdserver: switch to proper int64Slice for sorting
raft: comments for TestNodeStep
etcdserver: use int64slice directly
Merge pull request #1060 from jonboulle/peers

etcdserver/etcdhttp: split out peers and add tests
Merge pull request #1059 from coreos/node_test

test node step
wal: change wal filename format

Make raftIndex section to be expected raftIndex of next entry.

It makes filename more intuitive and straight-forward.

The commit also adds comments for filename format.
Merge pull request #1045 from unihorn/119

wal: change wal filename format
raftLog: compact applied entries only

compact MUST happen on entries that have been applied, or
1. it may screw up the log by setting wrong commitIndex
2. discard unapplied entries
Merge pull request #1049 from unihorn/120

raftLog: enhance check in compact
raft: test node block proposal
raft: test contain updates
raft: add isStateEqual test