Mimic Opera 12 handling of tabs

Open (pop-up) Sidewise window on CTRL-TAB, allow navigating through tabs with CTRL-TAB / CTRL-SHIFT-TAB and close Sidewise window + switch to the tab upon releasing the keys. So that mouse is not even needed.
That was a unique and very convenient with multiple open tabs feature of Opera.

If it is also possible optionally to close altogether the tab bar in the browser itself - even better. It is not useful with many open tabs anyway and not needed when Sidewise is installed.