client HTTPClient __init__ fails if auth_url None

The initializer for the python-cinderclient HTTPClient class
fails if passed a None for an auth_url.
This patch modifies the inializer to not call rstrip
if auth_url is None, matching the initalizers in
python-novaclient and python-neutronclient

Change-Id: I19dd6911816639a0e0d6175ba910e9777a4b5981
Closes-bug: #1358926
Updated from global requirements

Change-Id: I29667c947e5b1c54c125cd569f8d60bae45824f1
Support Volume Backup Quota

Python-cinderclient support update volume backup quota.

Cinder server side commit for this feature was:
https://review.openstack.org/#/c/111460/

blueprint volume-backup-quota

Change-Id: I1fceeb9fc0eb92370e249c46749a61e4b11420b0
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
Add the parameter bypass_url to the cinder client

If the bypass_url is specified in the http client, there is no need
to get it from Keystone.

Change-Id: I891849f77ad2ba98a83c993b401121216c8cfff6
closes-bug: #1350702
Merge "Add the parameter bypass_url to the cinder client"
Merge "Updated from global requirements"
Merge "Use newer features from keystoneclient"
Merge "client HTTPClient __init__ fails if auth_url None"