Improved Mobs 1.13

Redo integration mod for difficulty:
- Config changed from true/false to OFF/ON/ADD
- OFF and ON behave as old true/false but ADD allows stacking on top of existing ones for even more mayham
- LevelZ and PlayerEX now has a multiplier config
Allow pehkui integration to be more configurable with size chance and flag for individual mobs
Disable overlay being shown with f3 debug toggled
Allow negative values for difficulty increase. To use that use | as a delimiter instead of -
Add config for line of sight requirements
Add breaking speed modifier config
Add armor trim chance

Improved Mobs 1.12.4

Modify target goal instead of remove and replace which should fix anconcurrent exception