Add SVG font support

In the beginning (well before launch), Brick had SVG font support. I don't quite remember why I got rid of it (I think it was because of space), but due to some persistent problems with OTF & TTF font rendering in Chrome on Windows, we might be bringing this back.

The PR adds support for an `s` flag, that triggers a media query to target Webkit browsers (beware: this includes  browsers on OS X as well). The SVG fonts are, of course, also included.

Addresses (or at least attempts to) #79.