kill fa-spin for perf (fixes #63)

Font Awesome, we need to talk. In 1994, people were [rendering 320p 3d graphics on Amigas in real-time](http://www.demoscene.tv/page.php?id=172&lang=uk&vsmaction=view_prod&id_prod=4541). Two decades later, you need half a core to animate your 32x32 spinning icon? Fuck off, buddy, just fuck off.