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/Activities/Repair.cs

@@ -71,7 +71,7 @@ namespace OpenRA.Mods.Common.Activities
 					return this;
 				}
 
-				self.InflictDamage(self, -hpToRepair, null);
+				self.InflictDamage(self, new Damage(-hpToRepair));
 
 				foreach (var depot in host.TraitsImplementing<INotifyRepair>())
 					depot.Repairing(host, self);