Change UpdateRules to account for 20181215 hotfix

OpenRA.Mods.Common/UpdateRules/Rules/20181215/RemovedAutoCarryallCircleTurnSpeed.cs

@@ -0,0 +1,55 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2018 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, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Collections.Generic;
+
+namespace OpenRA.Mods.Common.UpdateRules.Rules
+{
+	public class RemovedAutoCarryallCircleTurnSpeed : UpdateRule
+	{
+		public override string Name { get { return "Removed AutoCarryall idle circling turnspeed hardcoding"; } }
+		public override string Description
+		{
+			get
+			{
+				return "Aircraft that circle while idle despite having CanHover (AutoCarryall) have their\n" +
+					"turn speed during idle circling no longer hardcoded to 1/3 of regular TurnSpeed." +
+					"Note that the new IdleTurnSpeed override works on all aircraft that circle when idle.";
+			}
+		}
+
+		bool showMessage;
+		bool messageShown;
+
+		public override IEnumerable<string> AfterUpdate(ModData modData)
+		{
+			var message = "While circling idle, your AutoCarryall(s) will now turn at full TurnSpeed,\n" +
+				"unless you manually define a custom IdleTurnSpeed.";
+
+			if (showMessage && !messageShown)
+				yield return message;
+
+			showMessage = false;
+			messageShown = true;
+		}
+
+		public override IEnumerable<string> UpdateActorNode(ModData modData, MiniYamlNode actorNode)
+		{
+			var autoCarryall = actorNode.LastChildMatching("AutoCarryall");
+			if (autoCarryall == null)
+				yield break;
+
+			showMessage = true;
+
+			yield break;
+		}
+	}
+}