Tone mapping (beta)

build/engine/shaders/const.h

build/engine/shaders/default/sky.ps

build/engine/shaders/default/terrain.ps

build/engine/shaders/gi/gi_propagation.cs

build/engine/shaders/hdr/hdr_adapt.ps

build/engine/shaders/hdr/hdr_luminance.ps

build/engine/shaders/hdr/hdr_reduction.cs

build/engine/shaders/hdr/hdr_tonemapping.ps

build/engine/shaders/lighting/lighting_blend.ps

build/engine/shaders/lighting/lighting_com.ps

build/engine/shaders/material/transparent.ps

source/ambient/Renderable.cpp

source/game/GameData.cpp

source/gcore/sxgcore.h

source/render/RenderPipeline.cpp

source/render/RenderPipeline.h

source/render/gdata.cpp

source/render/gdata.h