Shader switches counter; Terrain shader (beta); Some improvements

build/engine/shaders/default/terrain.ps

build/engine/shaders/lighting/lighting_blend.ps

build/engine/shaders/ppgensm/ppgensm_pssm.ps

build/engine/shaders/sky/sky_box.ps

sdks/graphix

source/game/GameData.cpp

source/render/RenderPipeline.cpp