fix mind controlled soldier crash
make sure unconscious units lose all their items properly.
fix some logical fallacies
mind controlled soldiers should not use mind control on soldiers
small fix for math error.
berserkers force fire :P
double safety

this shouldn't really be necessary, when converting a unit, they are
absolutely always dead. but in case someone decides to add a way to
revive units from zombification, it might be nice if their inventories
weren't messed up.