Make the models use hardware shader skinning

Currently the animated models in the client are animated using software skinning. That means that for each frame all vertices are recalculated on the CPU and sent to the GFX card. This is very resource hungry, both in CPU cycles and bandwidth. A much better approach is to use a vertex shader to calculate the positions on the GPU. The GPU is very much better at such calculations, and this would save the bandwidth. Ogre already has some nice support for enabling hardware skinning, but the main problem is that our models have way too many bones for the standard shaders that come with Ogre. We therefore either have to create new shaders ourselves, or alter the models so that they can be animated using the existing shaders.