* Refactor helper function that builds the map of http status codes
to local http exceptions - now we don't have to explicitly list
every single exception name
* Add several exceptions to represent http status codes that were not
previously represented
* Improve consistency of exceptions naming by prepending 'HTTP' to
necessary exception names
* Use HTTPException instead of ClientException
* Deprecate old http exceptions (those that aren't prefixed with HTTP)
* Deprecate ClientException
* Deprecate unused NoTokenLookupException and EndpointNotFound
* Add test module to spot-check the from_response helper
Change-Id: Ibc7fef9e2a5b24bd001d183d377901f302d650a9
Monty Taylor