V4

• Add more output color space selections (now you can mirror the input color space) (can be useful with RESTIR, to make AutoHDR apply before UI)
• Added separate "Color Space Conversions" shader (can be useful with RESTIR, to make AutoHDR apply before UI, with linearization at the end)
• Added new "source HDR peak brightness" setting to specify how much the HDR game would have originally tonemapped to (e.g. older Unreal Engine exclusively targeted 1000 or 2000, this can now remap from an exact value to your specific display peak)
• Defaulting to gamma 2.2 for SDR now
• Improved math and avoiding NaNs
• Improved commenting and naming and tooltips