Remove passing the warheads from DamageWarhead to AttackInfo.

Added a Damage class to pass damage value and damage(types) instead.
This removes a great amount of overhead and longterm opens possibilities to have damagetypes without warheads.

OpenRA.Mods.Common/Traits/Infantry/ScaredyCat.cs

@@ -78,7 +78,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public void Damaged(Actor self, AttackInfo e)
 		{
-			if (e.Damage > 0)
+			if (e.Damage.Value > 0)
 				Panic();
 		}