Initial restructure of Reddit classes and some OAuth changes.

Current structure:
- BaseReddit
  - OAuth2Reddit
  - UnauthenticatedReddit
    ** AuthenticatedReddit (inherits from both the above)
       - LoggedInExtension (to be refactored)
       - SubredditExtension (to be refactored)
         ** Reddit (inherits from both the above)

The goal with the new structure is for all super classes to be directly
usable. Instances of these classes simply will not have the additional
functionality provided by their subclasses.

Renamed get_access_token to get_access_information and include the scope.
Renamed refresh_access_token to refresh_access_information.

Finally, this change allows for non-https based OAuth (for development).