Fix for 2811 (dsreplication disable doesn't remove references to current server from replicated servers)
The fix makes dsreplication enable and dsreplication disable symmetric.  When the user disables the last replicated suffix, we inform that the replication server will also be disabled.  So when the last repilcated suffix is disabled, replication on cn=schema and cn=admin data are also disabled and the registration information updated properly.

Some changes have been made in ADSContext to make registerServer and unregisterServer symmetric: unregisterServer removes the references to the server keys and also the references to the server in the different server groups.

The code of DsFrameworkCliServer.java has also been updated since ADSContext.unregisterServer already updates the server groups.