Simplify

I took a very simple approach to this. So far it has seemed to work out pretty well for me here: https://github.com/slamdata/slamdata. There's probably a whole slew of bugs in here waiting to come out, but I thought this might be a nice start for a rewrite.

Please review/comment/suggest.
One of the goals of this PR is to keep it as close to react as possible, since `createClass` is what they use, I think we should stick with it. When they change terminology/api, we should follow suit. I think changing the name would just be too confusing to newcomers of this wrapper.