Convert model code to use vertex attributes instead of deprecated glBegin

Hi, I've noticed that the rendering code is using deprecated glBegin/End functionality and decided to rewrite it to use a more recent OpenGL vertex data representation, vertex attributes. Testing has been done with kotor2.

The code is the groundwork for more interesting things like shaders (GL >= 2 functionality). It is still OpenGL 1.1 compatible (I think, hehe)  using fixed function API and is not optimized by any means, doesn't use VBOs yet, no state caching or culling. But then given the age of the games it should be fast enough I guess.

There are a few minor gotchas atm. NWN mesh loader needs some testing. I'll try to get a NWN copy. The NWN ASCII loader is broken. Is this loader a requirement btw?

Anyway, have a look and tell me what you think.