[ Request ] Downsample in linear color space

[milesrotaru]

The ParaLLEl RDP plugin has an option to downsample the final output, which is often used in conjunction with a 2x or higher rendering resolution to achieve super-sampled anti-aliasing. I found that using a gamma-correct bilinear downscaling shader setup achieves nicer looking results. (no dark halos where opposing colors meet) While this shader setup solves the problem, it would save some hassle to have it built into the core.