new mobs

• By opening this merge request, you agree to release your code and all other changes under the GPL 3 license and to abide by the terms set by this license.
• Significant changes of this merge request have been added to the changelog.

Changes:

• bring relevant mob skeletons in-line with humans, utilizing configs and setting up species/gender traits to describe mobs
• add "critter" skeleton for very small scale mobs
• bring the number of non-humanoid species in-game from 2 to 30
• correct inconsistencies in naming scheme and load.rs formatting
• realize i've been doing everything wrong
• panic
• get sharp and zesterer to carry me out of trouble
• finish setting up versatile skel_attribute system
• simplify config format and haul out all the mistakes
• rebuild all the mobs
• bring everything to full animation