Implement toolbar+tab button

<CarlosRuiz> JanThielemann, about your comment on
<CarlosRuiz> we have toolbar button column as Y-toolbar N-tab
<CarlosRuiz> I think it could be good to add an option B-Both - to show a button on the toolbar and on the tab
<CarlosRuiz> WDYT?
<nmicoud> +1 for me