include stats from BaseViewsReport in SyncGatewayReport

Change-Id: Ib5aa921c3c8c0ff3442d4685cf3eb7eb5c7cdb4e
Reviewed-on: http://review.couchbase.org/30279
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Pavel Paulau <pavel.paulau@gmail.com>