ReplicationIterator.java:
Renamed releaseCursor() to close().
Now extends Closeable.

*.java:
Consequence of the change to ReplicationIterator.

MessageHandler.java:
Removed releaseAllIterators() in favour of StaticUtils.close().

ReplicationBackend.java:
In getEntry(), used early exit.
Used StaticUtils.close().
Removed useless comments / code.
Used interfaces rather than concrete classes.
Extracted methods computeDN() and writeChangeRecord().

ReplicationServerDomain.java:
Removed sleep() replaced with StaticUtils.sleep().

StaticUtils.java:
Made close(Collection) more generic + now log exceptions happening when closing.