More Apparel Layers

[Project 06]

I discovered that while updating my old mod that some apparel layers were removed, I'm guessing because they weren't used by vanilla items so they were deemed unnecessary. However these extra apparel layers allowed modders such as myself to add new equipment without it interfering with vanilla or standard gear. I tried adding in new layers myself but that required rebuilding a new ThingDefs just for my mod, and wound up also requiring me to rebuild Pawns as well so I knew at that point it would be impractical if not impossible to do this. Just a few extra layers for modders to play with would be great.