xapp-status-icon.c: Update all icons when we lose or regain our
identity on dbus.
xapp-sn-watcher spawns multiple icons from a single process. It
only has a single name on the bus but exports multiple paths for
the icons. If the name is lost or gained, all icons should react.
sn-item: Don't update the id property unless it has changed.
This can also cause extra updates (though not recursive), which
causes visual issues with apps that provide frequent graphic updates
to the icons (like indicator-multiload).
xapp-status-icon.c: Make XAppStatusIconState per-process.
Since we started supporting StatusNotifier, xapp-sn-watcher
proxies for all StatusNotifier/AppIndicator apps' icons. So
a single name is owned on dbus (for sn-watcher), with multiple
exported interfaces on unique paths using an object manager.
The XAppStatusIcon class is still only a single icon only class,
and the object manager is a singleton. Since we only try to
own a bus name for xapp-sn-watcher, on_name_acquired was only
being called once, even though the icon states were per-icon,
so only the first icon from xapp-sn-watcher was being set to
'native', and certain things only happen for native icons,
like updating Primary/SecondaryMenuIsOpen.