Added ability to join a server on startup, for gamelist apps.

OpenRA.Game/Game.cs

@@ -388,5 +388,22 @@ namespace OpenRA
 		{
 			return orderManager != null && orderManager.world == world;
 		}
+
+		public static void JoinExternalGame()
+		{
+			var addressParts = Game.Settings.Game.ConnectTo.Split(
+				new [] { ':' }, StringSplitOptions.RemoveEmptyEntries);
+
+			if (addressParts.Length < 1 || addressParts.Length > 2)
+				return;
+
+			var host = addressParts[0];
+			var port = Exts.WithDefault(1234, () => int.Parse(addressParts[1]));
+
+			Game.Settings.Game.ConnectTo = "";
+			Game.Settings.Save();
+
+			Game.JoinServer(host, port);
+		}
 	}
 }