added repair activity; not wired up for FIX yet

OpenRa.Game/Traits/Activities/Repair.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace OpenRa.Game.Traits.Activities
+{
+	class Repair : IActivity
+	{
+		public IActivity NextActivity { get; set; }
+		bool isCanceled;
+		int remainingTicks = ticksPerPoint;
+
+		const int ticksPerPoint = 15;
+		const int hpPerPoint = 8;
+
+		public IActivity Tick(Actor self)
+		{
+			if (isCanceled) return NextActivity;
+			if (--remainingTicks == 0)
+			{
+				self.Health += hpPerPoint;
+				if (self.Health >= self.Info.Strength)
+				{
+					self.Health = self.Info.Strength;
+					return NextActivity;
+				}
+
+				var hostBuilding = Game.FindUnits(self.CenterLocation, self.CenterLocation)
+					.FirstOrDefault(a => a.traits.Contains<RenderBuilding>());
+
+				if (hostBuilding != null)
+					hostBuilding.traits.Get<RenderBuilding>().PlayCustomAnim(hostBuilding, "active" );
+
+				remainingTicks = ticksPerPoint;
+			}
+
+			return this;
+		}
+
+		public void Cancel(Actor self) { isCanceled = true; NextActivity = null; }
+	}
+}