cluster/dht: node-uuid for directories winds to all subvolumes

this works similar to pathinfo now except that the request is sent
to all subvolumes of dht. Underlying replica selects it's subvolume
in a round-robin fashion till one of them returns successfully.

Change-Id: Ie46c5f7090d04d8c2e487b209916ae6791e94624
BUG: 847839
Original Author: Venky Shankar <vshankar@redhat.com>
Signed-off-by: Avra Sengupta <asengupt@redhat.com>
Reviewed-on: http://review.gluster.org/5225
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>