Added a new Leaving Status for ServiceMembers allowing a clean shutdown
Merge branch 'master' into jn-clean-shutdown

Conflicts:
	nrv-core/src/main/scala/com/wajam/nrv/consistency/ConsistencyMasterSlave.scala
Fixed explicitReplicaResolver to keep Master Node's status, removed leaving target node outgoing calls handling
replaced sleeps with latchBarriers, various fixes after code reviews
added default timeout for shutdown
code review fixes
fixed comments
fixed stop for StaticClusterManager
Merge pull request #192 from wajam/jn-clean-shutdown

Jn clean shutdown