WT: Replace Model allows only triangulated faces, not quads.

[FeralPotato]

Importing meshes with quads works only with the Import Mesh function. Importing a model using the Replace Model function will fail when not all faces are triangulated. The meshes get torn apart:

In the screenshot you can see that the torso got split into two disjointed parts, which are regarded as two different body parts instead of just one, resulting in the mesh count being too high.