Tweaks some rendering and world generation related things to make the game a bit more colorful (again).

* Tweaks which tree types are generated in which biome types (since the Plain biome is quite common, there should be more tree variations than one, there should be no trees in deserts, ...)
* Reduces the overall fog density drastically
* Increases the amount of Lambertian (diffuse) lighting applied to normal chunk blocks
* Changes the configuration of the filmic tonemapping operator
* Replaces the good ol' grass LUT with a new (more colorful) one
Renames some of the rendering related Performance Monitor activities and adds a missing endActivity() call.