Implemented move_cost and is_passable
Added cost and passable functions to the reachable call. Made the passable info for the bar depend on the selected unit.
Removed load function. Made A*  functions depend on unit cost and passable functions.
Merge branch 'master' of github.com:TheLastBanana/tactics

Conflicts:
	gui.py
Merge branch 'master' of github.com:TheLastBanana/tactics

Conflicts:
	gui.py