Renderers can now cope with parameterised args.  ResponseMixin gets cleaned up & added Renderer.can_handle_response(), mirroring Parsers.can_handle_request()

All top level modules are included. Ready for diving into the modules and documenting/ enhancing already existing docs.

Getting rid of all errors and warnings that show up when building the docs, to make a clean start with the library documentation .

--HG--
rename : docs/library/authenticators.rst => docs/library/authentication.rst
rename : docs/library/emitters.rst => docs/library/renderers.rst