_id_counter is now an instance variable.
Moved protocol basics into protocols/__init__.py.
Moved exceptions into own module.
Removed create_error_response.
Updated docs on protocols.
Replaced RuntimeErrors with proper NotImplementedErrors.
Added missing exceptions file.
Added dispatch implementation and tests.
Added dispatch documentation.
Dispatch warrants a version bump.
Version bump in docs.
Added docs on missing transports.
Removed redundant backslash.