CBQE-2162 Add Check point parameter:: High level tests for checkpointing in XDCR

Change-Id: Ie220946fe85da426406a71c3f6439cf702ce2bc7
Reviewed-on: http://review.couchbase.org/35061
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>