Desertify Terrain - 1.7 compat

- Changes terrain to use desert textures
- Changes behaviour of the terrain to resemble sand
- Some lighting changes
- Removes most trees, keeps bushes

Thanks to Kexanone for his WINTERIZE addon. It was incredibly easy to make this mod using that as a starting point.

Better used along GL!TCH's lighting overhaul for desert envs: https://reforger.armaplatform.com/workshop/673957072A2CC77C-L.W.ODesert