[DONE][Suggestion] Option to override item used for self destruct

[Nord]

Looks like "specab" does not work, if unit's armor have not only "corpseBattle" but "corpseGeo" too, and geoscape corpse item have no "power".
I can add power to geo corpse, but it will make different units explode with the same strength, and this is not good.

[Yankes]

OXC use globe corpse, because of this OXCE behave same, I would like to change it but this could break some mods.

Code: [Select]

if (_attack.attacker)
{
itemRule = _attack.attacker->getArmor()->getCorpseGeoscape(); //TODO: not getCorpseBattlescape ones?
_power = itemRule->getPowerBonus(_attack);
_damageType = itemRule->getDamageType();
_radius = itemRule->getExplosionRadius(_attack);
if (!RNG::percent(itemRule->getSpecialChance()))
{
_power = 0;
}
}

Probably without consensus of all major modders it can't be changed.

[Meridian]

Done: https://github.com/MeridianOXC/OpenXcom/commit/d13c4bebe6a825a78bbee52e0b5445a2192070d0

There is a new attribute `selfDestructItem` on the armor, which is used instead of `corpseGeo`.
(corpseGeo still works if selfDestructItem is not specified)