JSCBC-919: Added support for XDCR custom conflict resolution.
JSCBC-919: Added support for XDCR custom conflict resolution.

Change-Id: I7e88545de0e47ba906f2d32f96f57504ad8a5ff6
Reviewed-on: https://review.couchbase.org/c/couchnode/+/167148
Tested-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>
Reviewed-by: Charles Dixon <e13bf4498b4994e133fd3586350658dc4a59329a@gmail.com>

brett19/couchnode,couchbase/couchnode,couchbase/couchnode,brett19/couchnode,brett19/couchnode,couchbase/couchnode,couchbase/couchnode