Fix vertex-blending (Skinning)

[JayFoxRox]

Trying to make sense of:

• https://docs.microsoft.com/en-us/windows/desktop/direct3d9/geometry-blending
• https://docs.microsoft.com/en-us/windows/desktop/direct3d9/vertex-tweening
• https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_vertex_blend.txt
• https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_matrix_palette.txt (not implemented?)

I'm trying to fix: https://www.youtube.com/watch?v=6Ufbyr33hKQ

This works fine in Cxbx-R: https://www.youtube.com/watch?v=CU9D3-cLFCI

No success so far.

[JayFoxRox]

Upstreamed; was a bug with mode order.