Add Glance support

Glance support in Cinder is used to convert images into volumes
or send volumes into Glance with the goal to boot virtual machines
from volumes.

Change-Id: Ie2c9ed382254e374d12242edc7d57077fbbcd240
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
(cherry picked from commit 5d91bf3210a9b25d724fc21068e22c9d322c27a5)
Merge "Add Glance support" into stable/havana