TODO
====

 - Unit tests against copies of current discovery docs

 - Flag required parameters

 - Check the regex when accepting values

 - OAuth cmdline sample should start local http server to catch response.

 - Caching of discovery doc


 - Layered user-agent header, ala 'my-buzz-client/1.0 google-api-python-client/0.2 httplib2/0.6'


 - Requests for multiple APIs at one time.

 - 2.x and 3.x compatible


DONE
====

 - Implement requests as Command objects, either for immediate
   execution, or for batching.

 - Add in 'Extra Discovery' for pagination