Since NotificationServer is a spawn-on-demand + die-when-not-used type
of service, we can't expect a singleton connection to it to remain open
and useful.
We solve this for now by making a new IPC connection for every new
notification sent. Maybe there's a better solution for this.
This patch adds NotificationServer, which runs as the "notify" user
and provides an IPC API for desktop notifications.
LibGUI gains the GUI::Notification class for showing notifications.
NotificationServer is spawned on demand and will unspawn after
dimissing all visible notifications. :^)
Finally, this also comes with a small /bin/notify utility.