String changes in gnome-control-center/Printers

[Marek Kasik <mkasik redhat com>]

Hi,

I've added authentication dialog to Jobs dialog of Printers panel in 
gnome-control-center. It requires these new strings:

"Authentication required"
"%u Job Requires Authentication"
"%u Jobs Require Authentication"
"Enter credentials to print from %s."
"Domain"
"Username"
"Password"
"A_uthenticate"
"_Authenticate"

Regards

Marek