Add support for FontAwesome icons

[justmytwospence]

I take no credit for fontawesome.sty myself, I just found it in a gist by Honza Ustohal and thought it was a nice touch to my personal fork. fontawesome-webfont.ttf, added to the fonts directory, must be installed as an OSX system font, after which this works rather seamlessly.

Example use:
\href{http://twitter.com/swaycz}{\twitter\ swaycz}

A number of definitions are included already in fontawesome.sty, but arbitrary new definitions can be included as well.