Per-bone Animation

First pass at per-bone animations, combining upper body and lower body actions.

This is all it takes to control this animation:

    //Load a model
    auto model = LoadModel(world, "Models2/merc/merc.mdl");
    auto bone = model->skeleton->FindBone("spine_01_Military_Male");

    //Main loop
    while (window->Closed() == false and window->KeyDown(KEY_ESCAPE) == false)
    {
        if (window->KeyDown(KEY_UP))
        {
            model->Animate("walk", 0.4);
        }
        else
        {
            model->Animate("idle", 0.4);
        }
        if (window->KeyHit(KEY_SPACE)) model->Animate("shoot", 0.25, 100, ANIMATION_ONCE, 0, bone);
         
        world->Update();
        world->Render(framebuffer);
    }