Content update:

- the dead farm has lighter/more dirt like ground now so it fits in better when used as a normal terrain on maps
- the quicksand terrain is lighter and more diverse color wise now to better fit dirt
- the moorland terrain is lighter now to better fit dirt
- the savannah terrain has a little more grass on it now
- the dirt4 terrain (new dirt/grass mix in AK) is less saturated now to better fit the other dirt terrains
- new cracked desert terrain that looks better when placed in large areas like on Nile Delta

Initial release.