Delete panel button. Fix #80.

![screen shot 2014-11-12 at 12 24 22 am](https://cloud.githubusercontent.com/assets/1996521/5005718/71cb3c02-6a02-11e4-9394-d071ed59d13d.png)

Now all the styles are in Sass, so the CSS file is compiled. This maps the minified CSS to the full Sass source so that it is nice for debugging in the browser's inspector.