Wit + other things that seemed reasonable.

So, this started as a general updates branch, but became a side project for a bit.

It adds Wit.ai natural language parsing, and along with that, things that made sense. The ability to prompt a user for a response or confirmation.

This ended up being pretty much a re-write of the core bitbot library, as well as the creation of a base responder that contained all existing responder features in a single place -- which led to the restructuring of the various responders.

Some responders were removed (annoying ones, and things that didn't work), and several have been added.

Ummm.. I'll be working at updating the documentation and building out specs, which I didn't do -- was "spiking" is my excuse.