This gives a more consistent normal distribution across directions.
I actually had to make the "normal region" of the light bigger, because
now the Clonk's face would be all dark otherwise. In the end,
everything looks smoother and less flashy now, which is probably as
it should be.
Also slight refactoring.
* intermediate fade triangles are now calculated in C4FoWLight
* rendering takes also place in C4FoWLight, using different C4FoWDrawStrategies
* solved an old TODO from Peter (int -> int32_t)
* refactor and simplify portions of the light vertex calculation code
Peter Wortmann