move all the Game.Exts junk either down into FileFormats or into WorldUtils

OpenRA.Game/WorldUtils.cs

@@ -137,6 +137,20 @@ namespace OpenRA
 						o.Subject, o.Subject.Owner.Country.Race))
 						return;
 			}
-		}
+		}
+
+        public static void DoTimed<T>(this IEnumerable<T> e, Action<T> a, string text, double time)
+        {
+            var sw = new Stopwatch();
+
+            e.Do(x =>
+            {
+                var t = sw.ElapsedTime();
+                a(x);
+                var dt = sw.ElapsedTime() - t;
+                if (dt > time)
+                    Log.Write("perf", text, x, dt * 1000, Game.LocalTick);
+            });
+        }
 	}
 }