Fixed [2.1.15] Bad lighting parity between resolutions

Going through my old stuff today, and I find that things aren't quite right. Here is a screenshot of an area at 640x400:



Now here's the same exact area running at 1280x800:



The FOF has become overly bright, and on a second glance, so has Sonic. This happens in both SDL and ddraw, and did not happen in 2.0.6.

There was some kind of fix for wall lighting not too long ago because in earlier versions higher resolutions had walls and sprites being drawn brighter than in lower resolutions. I'm guessing the fix didn't work for sprites and FOFs somehow.

Hm, that's interesting. I guess it wasn't as noticeable as the obviously mismatched brightnesses right now.

GODDAMNIT

I'm pretty sure I know what the issue is. I didn't apply the fix to, like was said earlier, FOF walls or some sprite cases. (Probably related to when multiple lights affect the sector or something) It'll be a simple fix, and while I'm at it I'll have to tackle another issue with FOF side lighting too.

Red took forever to fix this despite it being simple, so I went and fixed it for him. =V

http://git.magicalgirl.moe/STJr/SRB2/commit/69a58d836963b0cd1c8325fa3b3162c1418debe9