When a unit is active, selecting an auto-goto point with the mouse, or pressing "5" on the numpad, then pressing 1-4, 6-9 on the numpad would cause the unit(s) to face in that direction.
i.e., when you select (but still have the mouse button pressed) a tile to the north, the unit(s) will face to the north. Move it south, and they face south. Or, with the numpad, hold "5", then 8 for north, and they face north - 2 for south, and they face south.
i.e., when you select (but still have the mouse button pressed) a tile to the north, the unit(s) will face to the north. Move it south, and they face south. Or, with the numpad, hold "5", then 8 for north, and they face north - 2 for south, and they face south.