change bultin themes to avoid copyright issues...

[eadmaster]

The current Mario theme is very nice but unfortunately the sprites, music and backgrounds are copyrighted by the Big N and there is a certain risk the project could be shutdown because of this.
Since we don't want this to happen the default theme could be swapped with a Tux-based like this, and the current Mario theme could be provided as a downloadable alternative.
This could also help adding a package in the official Debian repositories.

[mmatyas]

If someone would create a complete, consistent theme that is close to the current look and feel, I'd be happy to use it. I'm pretty sure someone started working on such a project years ago, with a few tilesets and characters already done, but I can't seem to find the thread on the forum... There was also an idea to download a number of randomly selected skins, maps, etc. from eg. smwstuff.net on the first launch, but that wouldn't really fix the legal issues either, and it has its own set of problems too.