QOS Specs - added edit feature

This builds on the new QOS functionality. It adds ability to
edit existing QOS spec key-value pairs

Partially Implements: blueprint cinder-qos-specs

Change-Id: I3b443df168843919ee34f68718ad11f97353bbd4
QOS edit, create, and delete functionality

This builds on previous patches that adds QOS Spec functionality
to the "Volume Types" tab within the "Admin" -> "Volumes" panel.

Partially Implements: blueprint cinder-qos-specs

Change-Id: I0cc6447f279358f739bbdd3eff7f068b0b87ba09
Set the correct min_disk size when creating volume from image

Sometimes the image min_disk size is specified in a property rather
than the min_disk attribute (for instance, after creating a snapshot
from an instance). This ensures that the correct tooltip and error
message are displayed in these cases too.

Change-Id: I0c7a87a6f00c4cc1a54f8b70e5df9bb1d05de866
Closes-Bug: #1368600
Merge "Set the correct min_disk size when creating volume from image"
Merge "QOS Specs - added edit feature"
Merge "QOS edit, create, and delete functionality"