UI freeze exception request for g-c-c's Printers panel

[Marek Kasik <mkasik redhat com>]

Hi,

I've implemented authentication dialog for print jobs in Jobs dialog 
inside Printers panel of gnome-control-center. It shows up only if there 
is a job which needs authentication. Then an infobar is shown in the top 
with number of jobs which needs authentication and "Authenticate" button 
which reveals a popup dialog for entering credentials. Clicking 
"Authenticate" button in it authenticates the jobs.
You were not able to authenticate such jobs before (although it is 
mostly needed only when you use a SMB printer which needs authentication).

One more change is that the Jobs dialog requests more horizontal space 
and ellipsizes long titles of print jobs.

The design was made by Allan Day and patches were reviewed by Felipe Borges.

You can see screenshots of this change here:
https://bugzilla.gnome.org/show_bug.cgi?id=758170#c19
https://bugzilla.gnome.org/show_bug.cgi?id=758170#c20

Could you approve this change?

Thank you

Marek