Revert publish log to trace level
Ability to drain transaction log replication source

It this mode, the source can read all transactions including the last consistent one. When not in this mode, the source do not read the transaction log beyond the consistent record of the last consistent record.
Use nonEmpty instead of !isEmpty
Merge pull request #194 from wajam/manu-consistency-checker

Ability to drain transaction log replication source
Fallback to slower consistency verification when store timestamp < log timestamp

In this situation there is a possibility that the last transaction log consistent timestamp is an uncommitted transaction (i.e. response not written successfully in storage). We must comparate the timestamp of the last committed transaction in this situation.
Merge pull request #195 from wajam/manu-last-committed-check

Fallback to slower consistency verification when store timestamp < log timestamp
Merge branch 'master' into manu-replication-publisher-test

Conflicts:
	nrv-core/src/test/scala/com/wajam/nrv/consistency/replication/TestReplicationSubscriber.scala
Enough ReplicationPublisher unit tests