Static shadow maps

I've implemented shadow maps for the terrain, which are generated at start-up. I'm going to create an external tool for creating those, which reduces the engines initialization time a lot.

It's useless for day/night cycles, it's just too slow, but it's a nice feature for games where the sun position won't change. What's cool too: You can merge the normals into the shadowmap which allows some kind of per-pixel lighting on old GPUs.

Mountain throwing shadow on the terrain (shadowmap + PPL):