Strange toolbox, upgrades to gibber

- Adds a new artifact styled weapon called ‘strange toolbox’, based on
Goon’s artistic toolbox. Basically a portable gibber that will
eventually eat you unless you feed it. Spawn for +fun or add in your mapping projects. 
- New variables for gibbers: xDir and yDir to change the direction of
meat slabs ejected (for mappers), allow_abiotic to allow abiotic items,
require_aggressive_grab to do just that. Doesn't change default gibber performance.
- Gibber accepts monkeys