Update EA-1.16 : Trade and Pyramids
Cities can now trade resources between them.
Desert Cities can now build pyramids.

Other changes :
- Increased the forest density to make them more believable.
- Updated Unity to 2017.2.2 : It should fix the issue of controller disapearing for WindowsMR users.
- Improved tree foliage color.
- Trees no longer collide between each other.
- Added decorative ground layers.
- Misc optimizations.
EA-1.16.1 :
- Fixed a small issue preventing raids to happen.