When the map is already aligned along the edge, the map were refocused
because there were not enough tiles shown beside the unit. If all
tiles are shown out to the edge of the map, we now don't refocus.

In positionMap I also changed
  bottomRow = y + bottomRows;
to
  bottomRow = y + bottomRows - 1;
Which I think is more correct, but I don't think it is really used.