Dump everything from catdb and HoTT-categories
Remove some already-ported files
Remove already-ported things from HoTT-categories
Add back morphisms, remove some ported catdb things
Remove ported things from catdb
Remove silly things
Remove subcategories

They were already ported
Remove subcategory
Remove DualFunctor
Remove things about to be ported
Remove ported grothendieck
Clean up ports
Move things to Old/ directory
Move things dealing with schemas

They probably won't get ported
Remove to be ported category of sections
Remove things to be ported
Add back Limits.v, which had some unported things