Multiplayer patch (mainly for multiplayer issues but a few small bug fixes too)
-Fixed NAT punchthrough doesn't work (Users are unable to connect to hosts who are behind a router)
-Fixed load game window tooltip shows wrong difficulty level
-Fixed trees look like dark squares after using alt-tab until you rotate the camera
-Fixed closed lines attract new passengers
-Fixed multiplayer find window tooltips show erroneous map name
-Better calculation of estimated maintenance expenses for stops supporting multiple vehicletypes
-Open windows can be closed by pressing ESC