Storage container mocking (and a few other mocking fixes)

Sending PR to rackspace first for review.

This PR implements storage mocking.  It also contains some minor fixes to load balancer mocking and compute mocking that were in my way.

I removed ```pending if Fog.mocking?``` from all the container tests and made them pass.  I haven't added all the other storage services, but container seems to cover the majority of actions.  I've also been testing it with some real-world applications, because the tests alone aren't enough to make sure it is a *good* implementation of mocking.