Checkpoint commit for OPENDJ-1206 : Create a new ReplicationBackend/ChangelogBackend 
 to support cn=changelog

Ignore unused domains when validating a server state for a changelog search. This was
the prior behavior withe ECL* implementation.

* ReplicationServer.java:
  Update validateServerState() method to ignore unused domain

git-svn-id: https://svn.forgerock.org/opendj/trunk/opends@10985 41b1ffd8-f28e-4786-ab96-9950f0a78031