Added new Extended Identity Tests: ChangePassword

### Changed

- Added the __ExtendedIdentityTest__ class as well as the __ExtendedIdentityFull__ ordered test.  This class will test the functionality for the Rackspace specific methods in the __IExtendedIdentityProvider__.
    - Added tests for: __ChangePassword__ method
- Fixed a bug in the __ProviderBase__ class which caused it to get a new token for each request instead of pulling from cache.
- Added __WaitForServerStatus__ (as well as __WaitForServerActive__ and __WaitForServerDeleted__) and __WaitForImageStatus__ (as well as __WaitForImageActive__ and __WaitForImageDeleted__) methods.  Currently these are blocking methods.  Async versions of these methods are still to come.
- Updates to the most recent version of the __SimpleRestServices__ client.