CBQE-912: xdcr tests with multi get/set ops

Change-Id: If655bc0935b312e76df013e817db3a41df0d96fd
Reviewed-on: http://review.couchbase.org/24404
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>