Bugfixes and polishes

Bugfixes:
+ Replace the bad path finding implementation by a performant library
+ Reduce the number of path finding for a given ant (no-task spam)
+ Bugfix the UI button when sprite behind
+ Fix queen die visually, the same ant corpse sprite is used
+ Fix the window not focused (tab out) "everyone die" bug

Game play:
+ Add keyboard shortcut for changing the job numbers: I, K, O, L

Adjust parameters:
+ Born rate set from 2s to 4s
+ Mushroom rate set from 1s to 2s
+ Add perlin noise for mushroom distribution, with more mushrooms down
+ Try to adjust a bit the "look for food" parameters