Updating bindings for ofLight and ofMaterial. Added ofFloatColor.

I left the current ofLight color setting functions as to avoid breaking existing projects. Though, I would recommend maybe removing the custom setters in favor of using ofFloatColor. I can do that if necessary.

Also, I can't take much credit for these changes as I'm bringing most of this over from the https://github.com/d3cod3/GAmuza project. It's nice that @d3cod3 did all that work, but I feel it should live in the ofxLua project. If accepted, I will most likely continue to bring over items and add things as I build my projects.