Refactoring w/ Compass

Hello,

I forked your code to simplify it using [Compass](http://compass-style.org/). My goal was to  change easily the class for each icon (for other projects). I separated the UTF8 chars from the CSS class.

I don't know if you want to merge it, but in case you're interested, here is a PR :)
To test it, just run `compass compile`.