A bit of refactoring
Wespen can now decide not to eat based on their life and pass their threshold to their children. Also slightly reduced their gain from food a bit.
Externalised the grid to an autonomous class (Gitter), added a phonebook to it (a cache of the grid cell in which each item is) to avoid recomputing the grid cell for immobile items.
Changed a lot of things, fixed some bugs (e.g. in inheritance) and added an escape mechanism to Emsen