MB-100: exposed dgm reb analysis to dashboard

Change-Id: I29ebe241c535a0953c6d7c55a1de0092652297f5
Reviewed-on: http://review.couchbase.org/28486
Reviewed-by: Ronnie Sun <ronnie@couchbase.com>
Tested-by: Ronnie Sun <ronnie@couchbase.com>