Finishes quota refactoring by making use of the new quota infrastructure.
Partially implements blueprint quota-refactor (the final piece is to
remove the old quota architecture).
This change is fairly substantial. To make it easier to review, it has been
broken up into 3 parts. This is the second part.
Change-Id: I1c8b43198f0d44e9e13a45575361aa043fd0639e
0daacfbf9b