Fixing UpdateOperationTest.csnGeneratorAdjust() test failure in Continuous Integration.

UpdateOperationTest.java:
Added consumeAllMessages(ReplicationBroker).
In csnGeneratorAdjust(), called consumeAllMessages().
Extracted local variables serverId.
Fixed formatting.
Increased vertical density.
Removed a useless call to Thread.sleep().
Removed useless comments.

ReplicationBroker.java:
Used local variables "localSession" to avoid concurrency issues when setSession(null) is called by another thread.

*.java:
Implemented toString().