planes attacking works; post-attack glitches though

OpenRa.Game/Traits/Util.cs

@@ -2,6 +2,7 @@
 using System.Linq;
 using OpenRa.Game.GameRules;
 using OpenRa.Game.Graphics;
+using OpenRa.Game.Traits.Activities;
 
 namespace OpenRa.Game.Traits
 {
@@ -135,5 +136,11 @@ namespace OpenRa.Game.Traits
 				.Product();
 			return mi.Speed * modifier;
 		}
+
+		public static IActivity SequenceActivities(params IActivity[] acts)
+		{
+			return acts.Reverse().Aggregate((IActivity)null,
+				(next, a) => { a.NextActivity = next; return a; });
+		}
 	}
 }