[Suggestion] Per-Model Culling Overrides

[ChloeDawn]

An addition to the model override implementation to allow culling of faces based on the same predicate approach as connect_to logic would be extremely useful. It could even potentially be handled on a per-quad basis, where each face of an element could have its own culling definition passed into CTM. Per-quad logic could rely on a tint-index system, much like the existing model overrides.