CBD-720 Allow passing compactor option to drop deletes

Change-Id: I18f6c826d6cb697c3f4a443f00cf64006ce8428f
Reviewed-on: http://review.couchbase.org/23835
Reviewed-by: Volker Mische <volker.mische@gmail.com>
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>
Tested-by: Damien Katz <damien@couchbase.com>