Fake damage cause does not affect on damage events

[Jjman739]

To reproduce this issue, create the following script:

on damage:
   message "%damage cause%" to victim

Then run the effect command !damage me by 1 with fake cause fire

It should say fire instead.

I think that this is caused by the damage script processing before the damage type is assigned, because the last damage cause expression still works as expected.

[Jjman739]

I don't know enough Java to reliably fix it myself, but I think I found the issue.

effects.EffHealth.java has this bit of code:

					HealthUtils.setDamageCause(entity, cause);
					HealthUtils.damage(entity, damage);

In bukkitutil.HealthUtils, the setDamageCause function sets the last damage cause:

	public static void setDamageCause(final Damageable e, final DamageCause cause) {
		e.setLastDamageCause(new EntityDamageEvent(e, cause, 0)); // Use deprecated way too keep it compatible and create cleaner code
		// Non-deprecated way is really, really bad
	}

Meanwhile, the damage function calls the damage event with the "CUSTOM" damage type:

	public static void damage(final Damageable e, final double d) {
		if (d < 0) {
			heal(e, -d);
			return;
		}
		if (!SkriptConfig.disableDamageCancelChecking.value()) {
			EntityDamageEvent event = new EntityDamageEvent(e, DamageCause.CUSTOM, d * 2);
			Bukkit.getPluginManager().callEvent(event);
			if (event.isCancelled())
				return;
		}
		e.damage(d * 2);
	}

It may break other things, but if the damage function was called with the damage cause as an argument, which is then passed into the damage event, it should fix this issue.