harvester actually sortof works now

OpenRa.Game/Traits/Activities/DeliverOre.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace OpenRa.Game.Traits.Activities
+{
+	class DeliverOre : Activity
+	{
+		public Activity NextActivity { get; set; }
+
+		bool isDone;
+
+		public void Tick(Actor self, Mobile mobile)
+		{
+			if (isDone)
+			{
+				mobile.InternalSetActivity(NextActivity);
+				/* todo: return to the ore patch */
+				return;
+			}
+
+			var renderUnit = self.traits.WithInterface<RenderUnit>().First();
+			if (renderUnit.anim.CurrentSequence.Name != "empty")
+				renderUnit.PlayCustomAnimation(self, "empty", 
+					() => isDone = true);
+		}
+
+		public void Cancel(Actor self, Mobile mobile)
+		{
+			mobile.InternalSetActivity(null);
+		}
+	}
+}