Fixed bugs concerning A* path finding.
Equipped inhabitants with their own pathfinder objects, which they now
	use to blithely walk around the entire map.

TODO:
	frequent operations in pathfinding is extremely expensive/slow. An adequate
		data structure for handling open nodes has to be designed to avoid
		repeated sorting of all open nodes in each and every step.

	A* heuristics have to be calibrated. Finding a path along 60 tiles currently
		takes between like 100 and 1500 iterations approx.