Added animation clip support
Animation clips can now be read from files
Started to implement blending

Also fixed an ugly bug in translation animation.
Crossfade and layered blending added

Some logic to go between tracks etc missing.
Both extra tracks support both types of blending

Simplified logic for adding new animation to tracks.
Pulled master

Normals funky
Fixed a bug with the animated model normals
Merge remote-tracking branch 'origin/master' into Temp_Blend_Animation