Rename "lightweight" to show up at end of node list

Change-Id: I5efdcca1471572e98b7af73ea6c55bc0e423320f
Reviewed-on: http://review.couchbase.org/43171
Reviewed-by: Chris Hillery <ceej@couchbase.com>
Tested-by: Chris Hillery <ceej@couchbase.com>