Remove the ascii protocol version of getl and unlock

we don't run memcached with ascii support

Change-Id: If4dfb6ec52186fc227793f0307049bf2e7446c3d
Reviewed-on: http://review.couchbase.org/25841
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>