xdcr 4x4 test spec targeted for windows testing

Change-Id: I43bdefddb7ccb966a4f6b76204a6de95d1241360
Reviewed-on: http://review.couchbase.org/43102
Reviewed-by: Venu Uppalapati <venumahesh@gmail.com>
Tested-by: Venu Uppalapati <venumahesh@gmail.com>