This implements numerous fixes for point lights, making them much more consistent than they are in vanilla. Most lights should no longer intermittently flicker.

This still has a couple of issues with some lights and some stages, likely due to the low per-object light limit. I don't fully understand the algorithm that selects lights yet, so I can't speak as to whether it's a mistake in the implementation, or just the engineer running out of light slots, but the next step will be bumping the per-object point light limit, likely to 8 or 16, as that's what the limit is on the CPU side.