Enhancement hook storage url

- Rename swifthook.py to openstackswifthook.py
- Remove AuthToken usage from everywhere that is unnecessary
- Disable the OpenStack and OpenStack Swift Hooks in default configuration
- Update the OpenStack Swift Hook to get the Storage URL from the Base64 JSON UTF-8 encoded X-Service-Catalog header field
- Add specific tests for the OpenStack and OpenStack Swift Hooks
- Add a Datacenter field to the Deuce Context which the OpenStack Swift Hook uses to determine which Storage URL to store in the context
- Removed unnecessary initialization of the Deuce Context, etc.
I would still prefer for drivers to be able to tell the app which hooks it needs, but we can do that later. This is a step in that direction.