Makes all volume-service interactions optional (includes
volumes displays and volumes portion of launch workflow).
Splits Instances & Volumes into separate panels to
facilitate Volumes being optional.
Adds an admin Volumes panel to complement the user
Volumes panel.
Adds the capability to mark Steps in a Workflow as
requiring a given service.
Implements blueprint nova-volume-optional.
Change-Id: I3fb4255617ae52be64e7a300afd691dc36b95586
2c0a8f3220