Cookbook overhaul for Grizzly.

Merging the cobalt renaming pull request into this one and adding a few additional changes to bring the cookbook up to date. This pull request now includes the following logical changes:

- Handling the package name and repository location changes due to the rebranding to cobalt.
- Provide an additional way to configure vms to use ceph by simply providing the rados and rbd pools. This was suggested in https://gridcentric.atlassian.net/browse/GC-46.
- Some clean-up involving obsolete and duplicated code.