touch popover: use underlines

The mnemonic underlines were 'sticking out' in the touch
selection popover.

https://bugzilla.gnome.org/show_bug.cgi?id=723621
printing: Fix visibility of tabs in print dialog

"Job", "Image Quality", "Color", "Finishing" and "Advanced" tabs
shouldn't be shown if there is no printer selected.

https://bugzilla.gnome.org/show_bug.cgi?id=724895
[l10n] Update Catalan translation