Last driver sync for Folsom and Grizzly

This is the last of the updates that I've been putting
off while trying to handle the core items in Cinder.

This change fixes the ctxt ordering error in volume_types
and also fixes and also changes the internal SolidFire
metadata storage to a single dict instead of a dict of dicts.

Change-Id: I002a591bc109ae1ab625c89f6ad841f60e464a40
(cherry picked from commit f53d48ebd9ff0e3b99470a9b95527c7054709c12)
Merge "Last driver sync for Folsom and Grizzly" into milestone-proposed