This patch addressed the following:
* Added a new create Consistency Group from CG Snapshot API.
- Note this is separate from the Create Consistency Group
API which requires volume types as the input.
* Added a corresponding driver API.
Conflicts:
cinder/volume/rpcapi.py
Partial-Implements: blueprint consistency-groups-kilo-update
Change-Id: I3a5f55d9dfd3fd4d70833824b29ebbd71986c143
adb4c80be8