basic Sync checking. No protocol stuff yet; just checks that input events are well-behaved.

OpenRa.Game/World.cs

@@ -12,15 +12,15 @@ namespace OpenRa.Game
 
 		public void Add(Actor a)
 		{
-			a.IsInWorld = true; 
-			actors.Add(a); 
+			a.IsInWorld = true;
+			actors.Add(a);
 			ActorAdded(a);
 		}
 
 		public void Remove(Actor a)
 		{
-			a.IsInWorld = false; 
-			actors.Remove(a); 
+			a.IsInWorld = false;
+			actors.Remove(a);
 			ActorRemoved(a);
 		}
 
@@ -52,5 +52,14 @@ namespace OpenRa.Game
 		{
 			return nextAID++;
 		}
+
+		public int SyncHash()
+		{
+			int ret = 0;
+			foreach( var a in Actors )
+				ret += (int)a.ActorID * Sync.CalculateSyncHash( a );
+
+			return ret;
+		}
 	}
 }