Very rough minimal editor example.

@mikeknoop @bryanhelmig 

Here's probably the right way to do pretty pills. Extremely rough right now, just a proof of concept. But this is a minimalist reactified editor that just uses plain old html so it can store keys in data attributes and do whatever styles we need. No funky layers to deal with. No unicode hiding. Lots of work to do around proper keyboard handling, but with some TLC, this is probably the appropriate thing to do. And it opens up other possibilities later, whereas the textarea hacks are severely limited.

I was originally opposed to trying to "re-create" CodeMirror, but I don't think that's really what we're doing. React actually makes this _relatively_ simple, and we're not trying to build a full-blown editor. Just something to handle the pretty pills.

![min-editor](https://cloud.githubusercontent.com/assets/404605/3710292/884b77a4-147f-11e4-87c2-d03682dbc793.gif)