xonotic: split glx, sdl, dedicated, data (#83461)

This has many advantages:
- Each variant can be installed without pulling in the dependencies of the
  other variants, which makes it possible to build an SDL variant
  without X11 dependencies
- Hydra can now build binaries without downloading 1GB of data, so users
  do not have to build them on their own machines
- Users do not have to redownload 1GB of data after each dependency
  update

Includes the following fixes:
- Add dependency on libGL for GLX variant as it will fail in some
  environments otherwise
- Pass -j and -l to make to enable parallel building
- Quote homepage URI and use https
- Add a .desktop file and icons

0 files changed, 0 insertions, 0 deletions