Use new SinglePartition partition scheme

SinglePartition is new partition scheme to specify the partition type
for indexes which reside on a single node. Projector doesn't
broadcast UpsertDelete message for this partition type.

Change-Id: Id1ee6220a30314da5384522cb43c3a253ba1e37e
Reviewed-on: http://review.couchbase.org/43412
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Tested-by: Pratap Chakravarthy <prataprc@couchbase.com>