Group smoothness and max angle doesn't affect vertex frame animations

[zturtleman]

Vertex normals for frame animations are always averaged regardless of the group smoothness and max angle settings.

May want to check max angle with the default pose so it matches skeletal models? [unconfirmed]

It seems necessary to add a new method to Model class to get frame animated vertex normal per-triangle (or group) and update the model exporters (MD2, MD3, ...) to use it.

[m-7761]

I've solved this in my fork by greatly simplifying Model to use one set of normals everywhere, no mode switching. But it does have the side effect of smoothing changes depending on the animation time (because normals change) if that wasn't ever the case for skeletal animation. I.e. the angle threshold means two faces may have a smooth angle at one time and not at other times.