Added CallFunc activity

OpenRa.Game/OpenRa.Game.csproj

@@ -137,6 +137,7 @@
     <Compile Include="Sync.cs" />
     <Compile Include="Traits\AcceptsOre.cs" />
     <Compile Include="Traits\Activities\Attack.cs" />
+    <Compile Include="Traits\Activities\CallFunc.cs" />
     <Compile Include="Traits\Activities\EnterTransport.cs" />
     <Compile Include="Traits\Activities\Fly.cs" />
     <Compile Include="Traits\Activities\FlyAttack.cs" />

OpenRa.Game/Traits/Activities/CallFunc.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace OpenRa.Traits.Activities
+{
+	public class CallFunc : IActivity
+	{
+		Action a;
+		public IActivity NextActivity { get; set; }
+
+		public IActivity Tick(Actor self)
+		{
+			if (a != null) a();
+			return NextActivity;
+		}
+
+		public void Cancel(Actor self) { a = null; NextActivity = null; }
+	}
+}