* Get the Quake 3 demo data to work with the open source Quake 3.

  quake3/demo takes care of downloading and patching the required PAK
  files.  quake3/wrapper calls the Quake binary with a synthesised
  directory of symlinks to activated PAK files.  This should make it
  easy to plug in the commercial PAKs, or third-party mods.

svn path=/nixpkgs/trunk/; revision=4611