Adds the tray icons implementation based on org.kde.StatusNotifierItem interface usage. Does allow restarting StatusNotifierWatcher object, but will fallback to XEMBED or internal tray, if wine gets initialized when there is no StatusNotifierWatcher object registered.
-- v41: win32u: Handle dbus notification balloons from system_tray_call win32u: Handle notification balloons through org.freedesktop.Notifications dbus interface win32u: Add a ShowBalloon driver interface win32u: Handle StatusNotifierItem management from system_tray_call win32u: Handle StatusNotifierWatcher owner changing and registering objects to a new watcher win32u: Add SNI driver for systray handling win32u: Add DBus event loop for SNI handling win32u: Add a SystrayRunLoop driver interface