Animation engine fundaments

I've been implementing the animation engine today in the character modelling program and also working up various parts of the bone animation system as required. There is now a rudimentary keyframe-based animation system that uses Catmull-Rom interpolation. As nothing can be saved or loaded I haven't done much playing around with it with more than two bones but it seems to be working fine. Some time before next week hopefully I can have it saving and loading stuff for a neat demonstration. Optional: tie in sprites too so we can see a character moving rather than just a skeleton.