made changes to support ibr

Change-Id: Ia3e04a65fe6d7e8b135ed5d50ab67ef167d1da4d
Reviewed-on: http://review.couchbase.org/37472
Reviewed-by: Thuan Nguyen <soccon@gmail.com>
Reviewed-by: Ashvinder Singh <ashvinder@couchbase.com>
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Ashvinder Singh <ashvinder@couchbase.com>