Java icon in system tray sometimes doesn't show up

The Java logo in the system tray slot for the new Java Plug-In sometimes doesn't show up. This seems to happen most often in cold start situations. The reason most likely is the new com.sun.deploy.ui.WindowsTrayIcon class added in 6611346, which decoupled the system tray icon support from the old Java Plug-In. In the interest of keeping the code simple the new code doesn't properly support the case where the image doesn't get fully loaded within a short period of time. A proper ImageObserver needs to be added and the code modified to support the icon's image being loaded asynchronously.