Multi-Threading and Storing Photon Maps

Well, since I'm running with a Core Duo I decided to implement multi-threading for the photon scattering step since thats where 90% of the time is spent. It works great and was very simple to do, required very little restructuring of my code.

And to add another speed book I made the photon map serializable so that I can save and load them to disk. It saves some time, but the deserializing process is

slow

and I mean slow. But it helps.

More to come later, this was just a quick note between renders.