printdialog: Handle nonexisting files better
When a non-existing file is selected in the file chooser for print-to-file, we weren't updating the button label to show the new filename. Fix that.
Also, use newer file chooser api.
When a non-existing file is selected in the file chooser for print-to-file, we weren't updating the button label to show the new filename. Fix that.
Also, use newer file chooser api.