ClonesProductionUnits:

string[] CloneableTypes	checks Cloneable.Types

Cloneable:
	string[] Types checked by ClonesProductionUnits.CloneableTypes

Added INotifyOtherProduction
	for notifying self when another actor
	produces a unit.

OpenRA.Mods.RA/Buildings/ClonesProducedUnits.cs

@@ -0,0 +1,50 @@
+ #region Copyright & License Information
+ /*
+  * Copyright 2007-2014 The OpenRA Developers (see AUTHORS)
+  * This file is part of OpenRA, which is free software. It is made
+  * available to you under the terms of the GNU General Public License
+  * as published by the Free Software Foundation. For more information,
+  * see COPYING.
+  */
+ #endregion
+
+using System;
+using System.Linq;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.RA
+{
+	[Desc("Creates a free duplicate of produced units.")]
+	public class ClonesProducedUnitsInfo : ITraitInfo, Requires<ProductionInfo>, Requires<ExitInfo>
+	{
+		[Desc("Uses the \"Cloneable\" trait to determine whether or not we should clone a produced unit.")]
+		public readonly string[] CloneableTypes = { };
+
+		public object Create(ActorInitializer init) { return new ClonesProducedUnits(init.self, this); }
+	}
+
+	public class ClonesProducedUnits : INotifyOtherProduction
+	{
+		readonly ClonesProducedUnitsInfo info;
+		readonly Production production;
+
+		public ClonesProducedUnits(Actor self, ClonesProducedUnitsInfo info)
+		{
+			this.info = info;
+			production = self.Trait<Production>();
+		}
+
+		public void UnitProducedByOther(Actor self, Actor producer, Actor produced)
+		{
+			// No recursive cloning!
+			if (producer.HasTrait<ClonesProducedUnits>())
+				return;
+
+			var ci = produced.Info.Traits.GetOrDefault<CloneableInfo>();
+			if (ci == null || !info.CloneableTypes.Intersect(ci.Types).Any())
+				return;
+
+			production.Produce(self, produced.Info, self.Owner.Country.Race);
+		}
+	}
+}