SL-18190 End of linear space odyssey -- just eat the conversions in atmosphericsFuncsF for sunlight and additive, but leave linear ambient in tact.

SL-18190 WIP -- Take 2 on linear space windlight (more methodical approach -- make desired interface but brute force color conversions). Placeholder PBR water and move to deprecate forward rendering shaders.

SL-18190 WIP - Windlight to linear space proof of concept, better parity between release viewer and materials viewer when reflections disabled.  Avoid run-away probe ambiance.

SL-18120 Fix for specular color of legacy materials tinting environment reflections from "environment" intensity.

SL-17705 Backwards compatibility pass.  Support OpenGL pre-4.0 by disabling reflection probes and anti-aliasing.  Get render parity with current release viewer when reflection probes are disabled.

SL-18190 Reduce banding (stay in linear space as much as possible, increase precision of reflection probes).  Faster radiance and irradiance map generation.

SL-18190 Don't allocate mips for irradiance maps because they're never generated.  Disable OpenGL core profile on Intel by default.

WIP - multiSpotLightF uses proper PBR shading, alpha is broken but pushing now in case my hard drive melts

SL-17701 WIP -- Correct color space management for base color and emissive color factors and textures.  Support for double sided alpha blended PBR materials.