main: remove query_params*.go
cfg/ -> conf/
all config -> cfg
etcd: replace buildServer with runServer in tests
etcd: rename initTestServer -> newUnstartedTestServer
etcd: cleanup tests
etcd: remove skipped test
etcd: defer afterTest
server: add testServer and testCluster
etcd: better testing...
server: more better testing
server: fix testings

Make WaitMode panic to alert.
etcd: make retry configurable
store: fix the bug caused by random iteration order over map
etcd: attach default scheme to the peer-list if scheme is not given
raft: add clusterId to snapshot
server: use random generated node id
snap: init commit
snap: better naming
snap: fix missing continue