Armor Trims Backport

Main Features:

Can now define items that can be trimmed (via the API). (GitHub Issue #4)
Added functions to the upgrade template generators in the API to turn recipes on and off using a Boolean Supplier (if you aren't a modder this doesn't affect you).

Bug Fixes:

No longer takes forever to load when using JEI. (Unless you have an insane amount of mods and at that point how the heck can your computer handle that?)
I (hopefully) fixed FPS drops from the HumanoidArmorLayer (basically any entity that can wear armor). Let me know if this is not actually fixed though.
Lastly, untrimming doesn't remove all NBT data anymore; it just removes the trim now.