The original client crashed (or survived by pure luck) when muzzle
flash offsets >210 were send. Our fix was to bail out, but that broke
some buggy mods... So just return and print an optional debug message.
This fixes issue #153.
This fixes a long standing and until now unnoticed bug with negative
colored dynamic lights. Since we never set the OpenGL renderer as out
renderer, remaining softrenderer code was executed and the corresponding
effects never rendered. This manifested itself in missing darkness
around the "gravity well" in rogue.