Code cleanup.
Removed useless duplicated javadocs for getMonitorData.


ServerHandler.java:
Extracted method releaseDomainLock().
Replaced lockDomain(boolean) with lockDomainNoTimeout() and lockDomainWithTimeout().
Removed duplicate code from MessageHandler.
Moved shuttingDown() to ServerHandler.

DataServerHandler.java, ECLServerHandler.java:
Consequence of the change to ServerHandler.

MessageHandler.java:
Moved shuttingDown() here from ServerHandler.

ReplicationServerHandler.java
Consequence of the change to ServerHandler.
In checkGenerationId(), used early exit.
Extracted method clearRemoteLSHandlers().
In processTopoInfoFromRS(), inlined local variables.
In hasRemoteLDAPServers() and getConnectedDirectoryServerIds(), removed useless and misleading synchronized blocks.