Fix nrv-extensions
Merge pull request #280 from wajam/alex-fix-nrv-extensions

Fix nrv-extension
Merge pull request #281 from wajam/clement-tx-delta

Add replication delta in replication session information
Merge pull request #282 from wajam/clement-tx-delta

Add support for persistence of master/slave replication lag in Zookeeper
Merge pull request #283 from wajam/clement-tx-delta

Fix replication lag computation bug
Implement changeMasterServiceMember in ZookeeperConsistencyPersistence
Fix changeMasterServiceMember return type & remove useless override
Merge pull request #284 from wajam/clement-tx-delta

Redirect traffic to slaves when master is down
Merge branch 'master' into clement-change-master

Conflicts:
	nrv-zookeeper/src/main/scala/com/wajam/nrv/zookeeper/consistency/ZookeeperConsistencyPersistence.scala
Merge pull request #285 from wajam/clement-change-master

Implement changeMasterServiceMember in ZookeeperConsistencyPersistence
Reverse maxReplicaLagSeconds and replicationResolver in ConsistencyMasterSlave