Annotate Class signatures
Add metaclass kwarg to Sphinx doc for class definitions
Reformat to 100 characters
Add items to TODO
Reorganize __all__ imports, bump version number
Clean up protocol Method and Frame objects

* Consolidate PartialMessage (which should have actually been called
  PartialMethod) into Method.
* Various small internal refactorings to improve code quality
Fix docstrings
Bump version