HDArmour refactors based on initial updates/tests #395

Also saw Radtech override the MaxCheat() method, figured it might be useful here as well?

This way addon armours don't have to reimplement the entirety of the HandleDamage() method just to tweak the damage formulas.

originaldamage was never being altered between creation & usage, so simply referring to the damage passed in here should be fine. It's used later on after it's been altered, outside of this method, which makes sense.

added check for ArmourChangeEffect to skip the blackout effect (Armor Plates do this)

This way child classes that only want to adjust how much protection their armour provides don't need to reimplement the entire damage/impact logic

also use HDF.Give() instead of A_GiveInventory

This can cause Spawn Replacers to mess with what was tossed, which should be guaranteed to end up being the item version of the HDArmourWorn.

(hdmb && !hdmb.bHASHELMET) would short-circuit to false with players, which would always return -1 penetration for headshots. Since the parameter is inverted, the check should be, too. This results in (!hdmb || hdmb.bHASHELMET) instead, meaning if the thing isn't an HDest Mob, or if it is then it needs a helmet.

Bullets & damage functions seem to account for impact location, plus with the HideousHelmet being exclusively head-based protection, the Leather Jacket being Torso + Arms, there's some potential to allow for more granularly defined armour coverage zones beyond a toggle for vanilla armours being only torso or "full coverage"