CBQE-0: add priorities to spatial view confs

Change-Id: I9782d9f4945bbf92457f5bd77680c7ab4e613691
Reviewed-on: http://review.couchbase.org/25781
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Deepkaran Salooja <deepkaran.salooja@globallogic.com>