Rewriting the whole program...

Started rewriting the whole program, this time it's intended to be a
raytracer and a pathtracer. Raytracing part is quite good already,
haven't started on pathtracing yet nor do I know anything about it.

New features include Material data structures, Cook Torrance shading and
an easy way to define any kind of shading methods for different surface
materials by yourself, and so on... Just a way better program in general
than my first, old project.