Implement GETL and UNL

Change-Id: Ifde96afbd760f59d6f01b57ee5f26f0eb42013ab
Reviewed-on: http://review.couchbase.org/27118
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>