[racket] SVG & bitmap%s

Hi all,

I think I remember seeing a while back that someone was looking for a
way to load SVG documents into Racket bitmaps. It turns out that with
FFI bindings to the RSVG library it's pretty easy.

Code snippet here if anyone's interested:
  https://gist.github.com/takikawa/5088103

It assumes you have a copy of the Racket SVG shiny logo from here:
  http://www.eecs.northwestern.edu/~robby/logos/

Thanks to Matthew for the `get-handle` bitmap% method.

Cheers,
Asumu