Reverted item stacking of all items.

+ Wrench: You can use them for some basic skeleton repair. It's on par with a basic first aid kit. Really cheap and uncraftable. So it's balanced.
+ All NPCs would use their splint kit on themselves and their allies.
+ All NPCs would do repairing on themselves and their allies.
+ Distributed wrenches to all NPCs that have at least a basic first aid kit at ther inventory, except Holy Nation, InHuman Trackers and Cannibals.