Finish the job by removing all the now-unused modules. This also allows
us to - wait for it - kill mox at long last. It's a great day in the
parish.
Partial-Implements: blueprint remove-nova-network-ussuri
Partial-Implements: blueprint mox-removal-ussuri
Change-Id: Ia33ec2604b2fc2d3b6830b596cac669cc3ad6c96