Major Item Bugfixes, Crafting Changes, and more!

Added "Nightmare Essence" to the game. Nightmare Essence is acquired by selling Nightmare Items to any vendor
Crafts on Nightmare items now require Nightmare Essence. This cost scales linearly with Chaos
All crafts now have a 100% chance to success. Rejoice in your rerolls!
Fixed a major bug that was reducing the number of items dropped, especially in the earlygame
Fixed a black screen abyss soft-lock that could occur if a Beastmaster ended a run with active avatars
Increased the performance of the pets