P0 tests for XDCR: Pause and Resume

Change-Id: I33a47b31e361e9e30a47e82a323e2a047392c90a
Reviewed-on: http://review.couchbase.org/34367
Tested-by: Aruna Piravi <aruna@couchbase.com>
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Aruna Piravi <aruna@couchbase.com>