Fast Micro AI: remove debug output
Fast Micro AI: add a dungeon mode
Fast Micro AI: Add closeness-to-goal to unit order criterion

How fast (in how many turns) the unit can get there remains the main
criterion, but if that is equal for two units, use the closer unit
first.
Fast Micro AI: use hex 2 steps beyond next hop for move evaluation

It results in a better evaluation of the best hex to move to when
distance criterion is used (that is, when we are not in dungeon mode).