Use newer features from keystoneclient

There are a number of functions that were implemented in keystoneclient
in response to needs from cinder and other clients.

Now that these were released in 0.11 cinderclient should make use of
them rather than keep its own versions.

Change-Id: I6444fc5bfd2d0505f9a7eb2c6068ab945ae5bb9b
Merge "Use newer features from keystoneclient"