
gnome-settings-daemon monitors smartcard insertion and removal events on the system and then exports a model of the current smartcard topology over the bus using the D-Bus ObjectManager interface. This commit adds the support code needed in gnome-shell to talk to the gnome-settings-daemon service. A future commit will use this code to inform the login screen when a user inserts a smartcard (so it can react appropriately) https://bugzilla.gnome.org/show_bug.cgi?id=683437