CBQE-1204: identify orchestrator in clusterStatus

Change-Id: I7aac7717cbda967b59facfc68ba0652939c08038
Reviewed-on: http://review.couchbase.org/25637
Reviewed-by: Chisheng Hong <chisheng@couchbase.com>
Tested-by: buildbot <build@couchbase.com>
Tested-by: Chisheng Hong <chisheng@couchbase.com>