OPENDJ-1053 (CR-2520) Improve logging of replication load balancing and fail-over in order to diagnose the causes of these events


This change records how each replication server is evaluated by computeBestReplicationServer().
It also logs why a DS switches from one RS to another RS.


ReplicationBroker.java:
Added static classes RSEvaluations and LocalEvaluation.
Moved keepBest() method to RSEvaluations.
In filterServersWithAllLocalDSChanges(), reworked the code to be more understandable + Added method getCSN() and rejectAllWithRSIsLaterThanBestRS(), rejectAllWithRSOnDifferentVMThanDS().
In computeBestServerWhenConnected(), extracted method isServerOverloadingRS().

replication.properties:
Added tons of messages.

ComputeBestServerTest.java:
Moved this class to package org.opends.server.replication.service to match the package of the tested code.
Consequence of the changes to ReplicationBroker.
Added methods containsOnly(), getDescription(), getEval1() and getEval2().
Reformatted the code a bit.
Removed @throws from javadocs.