Simple overlay for 32bit mesa drivers including llvmpipe

The overlay compiles 32bit libraries for 64bit systems - it doesn't install includes and only installs binaries when they're really needed

It's recommended that you keep you're 32bit and 64bit libaries in sync ie using the 9999 versions for both

Please report all bugs via https://github.com/FireBurn/Overlay/issues

Thanks and happy gaming