String freeze break request for gnome-shell

[Giovanni Campagna <scampa giovanni gmail com>]

Hello release team, hello translators,

I'd like to break the string freeze for gnome-shell for bug
https://bugzilla.gnome.org/show_bug.cgi?id=683060. The main part of it
is already solved, what is left out is handling DBus errors that might
happen even if GDM is available and the right version.
There is only one string, "Authentication error", and in the normal
case it should be never shown to the user. In fact, I've never
experienced such problems myself, but
https://bugzilla.gnome.org/show_bug.cgi?id=684172 tells me otherwise.
Without the patch, the shell is left with a broken greeter (half
animated avatar, no prompt) or unlock dialog (full grey screen). With
the patch, "Authentication error" is shown for a few seconds under the
entry (in the same place as "Authentication failed"), and the greeter
is reset or the lock screen curtain falls down again.

Thanks in advance,

Giovanni