CBQE-1164: update celery routing for kv tasks

make sure all kv tasks have a corresponding routing_key => queue. also ignore_results for tasks when not needed

Change-Id: I6e71b48f559a04458fcc6e0661d9fcdd03368d61
Reviewed-on: http://review.couchbase.org/25317
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Tommie McAfee <tommie@couchbase.com>