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.
@raxyu - I originally had 'iad' in there, but then figured it would be better to be more generic. I could go either way. Even if I did put in 'iad' you may still have to update your config if you are running in another DC (e.g ORD). (I normally use IAD myself.) So any default value could require a change in the config.

@painterjd - thoughts?