Design and implement skeletal animations subsystem

[Witek902]

• modify NFM format to support bones information (bone hierarchy, bind pose, bone weights per vertex and animations)
• implement skinning in vertex shaders
• implement animations mixing and bones transformations
• [MINOR] implement ragdoll physics via binding bones to a skeleton made of rigid bodies

TODO: How to import bone information? Maybe a python script for Blender would be helpful?

[lookeypl]

I'm wondering if this fits more into "Making nfEngine useable" or "Second release" milestone... On one hand, game engine without skeletal animations is not a game engine, on the other it is a very huge feature which probably won't make it into first release. What do you think?

[lookeypl]

Some things, which came up after yesterday's meeting:

• The skeletal animations subsystem should be enough to support all possible animations (rigid body and cel animations are not needed, at least for now. These could be a potential feature in the future)
• Animations subsystem should support states and switching between them:
  • Switching between animations should be smart, ex. a specific part of an animation should transition in one way, and other part in some other way.
  • All should be easily configurable and possible to easily create relations between states
• We still don't know how to keep animation-related data - whether this should be a part of NFM file, or maybe a new (NFA?) resource.