Add a comprehensive lighting system

[soulweaver91]

The lighting system has to be able to handle:

• The lighting inherent to the player in each view
• An unlimited (not really, but at least implemented in a way that a max number doesn't end up as a problem) amount of light sources
• Two light layers: one behind the actors, where all the intense light caused by running, bullets flying, etc. resides, and one in front of the actors, for the regular lighting effects