CQBE-0: Fixing timeout issues and logs improvement for rebalanceXDCR.py
tests

Change-Id: Icf28f951363eced03267957cefadee4bebc0c412
Reviewed-on: http://review.couchbase.org/30382
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>
Tested-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>