CGBLT-319:  pkg prefix:  couchbase-sync-gateway-{edition}

Change-Id: I4fae97ce77533bc7c758c788ecf32ca316636fd5
Reviewed-on: http://review.couchbase.org/38621
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>