Fred: replace wesnoth.dofile by wesnoth.require
Fred: fix parameters passed to zone_action_hold()
Fred: reactivate sending units into zones with too many unowned villages

This is mostly here so that two units will be sent to grab villages in
the west even if only one can get to a village on the second turn (but
it does have more general applications).
Also adapt to using gamedata tables.
Fred counter attack: fix a bug when units without MP are involved in an attack

Previously they were taken off the map afterward.