CBQE-1134: new cluster status object

every 10s, check cluster topology has changed.  this way we can make a new master when it's rebalanced out and do load balancing.

Change-Id: Ide3f1ca0ab315f0abd268f6879d588348a16617b
Reviewed-on: http://review.couchbase.org/25251
Reviewed-by: Tommie McAfee <tommie@couchbase.com>
Tested-by: Tommie McAfee <tommie@couchbase.com>