Rework clothing system, revamp existing outfits

ClothingMesh is now a resource type. Clothing items can have multiple meshes associated. The meshes have new options for material overlays, shadows, HLODs, and partial removal. The old ClothingMesh class has been renamed to ClothingMeshInstance.

Clothes can now be partially removed, such as pulled aside or unbuttoned. The only clothes using this currently are the panties.

The clothing meshes used are now higher poly and no longer clip through the body. There are rims on most clothes and two UV maps on some.

There is now a dither transparency fade when clothes are put on or taken off. This is provided by a new clothing shader. The shader will likely recieve more features later, such as for when clothes get wet.

Some of the rigging is not perfect and a few of the clothes don't have new textures. This can be done later.

Closes #3 (closed) and #4 (closed).