ReplicationServerDomain.java:
Changed getCount() return type from int to long (This change goes along with r9386).
Extracted method addUpdate(), isDifferentGenerationId(), isSameGenerationId(), collectRSsEligibleForAssuredReplication(), toRSInfo().
In many places, renamed sid to serverId.
Various cleanups:
- converted comments to javadoc
- added curly braces around if bodies
- collapsed if statements
- used interfaces instead of concrete classes
- removed useless parentheses
- removed useless 'this' qualifier in non static method calls
- put code on one line where it fits


MessageHandler.java:
In add(), removed unused parameter MessageHandler.
In getOlderUpdateCN(), removed useless reassignment of a local variable.