Nice project:
http://www.nongnu.org/mingw-cross-env/

It basically does what we do in cross.txt.

Pros:
- Can check for new upstream releases
- Dependency system
- Maintained by other people so we don't have to do it
- More packages
- Uses the new .pc files in SDL_* to handle indirect static
  dependencies (Libs.private)

Cons:
- Only support static linking (no .dll's) - is that a problem actually?
- I don't see DX support in SDL (should introduce latency in SDL_mixer)
- FreeType compiled without the patents-threatened parts, hence
  incompatible font display / metrics
- Still need to compile (not binary releases)

We see that it would save us time, but at the same time we'd need to
patch it to keep full precise control of the configuration.
