I've pushed a new notification to gnome-settings-daemon. It informs user
that a print job which needs authentication was sent to a printer (see
https://bugzilla.gnome.org/show_bug.cgi?id=766563#c10). Clicking on it
will open gnome-control-center's Printers panel with opened Jobs dialog
where user can authenticate such jobs.
The new strings are:
"%s Requires Authentication"
"Credentials required in order to print"
The freeze exceptions were approved by Piotr Drąg, Alexandre Franke,
Michael Catanzaro and Olav Vitters.
Thank you all for your help with this and I'm sorry for such late addition
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