Chest Cavity 2.13.0

Additions:
-Goats, Glow Squid, and Axolotls gained chest cavities
--Goats are herbivores with springy muscles, which increase jump height and reduce fall damage.
--Glow Squid have large fish chest cavities
--Axolotls have small aquatic carnivore chest cavities
Changes:
-Minecraft version update to 1.17.1
-Default drop rate increased to 10%, as 3.5% made actively seeking specific organs painful.
-Drop rate boost per looting increased to 4%, to continue roughly doubling drop rates at looting III.
-Rabbits now have small springy muscles instead of small animal muscles
-Zombie, Skeleton, and Spider chest cavity drop rate multipliers reduced to .3, .5, and .7 respectively.
Bugfixes:
-Horses now properly generate swift muscles
-Fixed broken GUI bug from pre-release.
-Fixed Active Blaze Rods only functioning as a full set