Better tooltips, add hot key

[KunibertSegensreich]

(I assume that has already been said, but my noob search doesnt show a hit.)

-- give all the tooltips way more descriptive content.
-- show the assigned hotkey in a dedicated area at the bottom of the tooltip in a slightly different color

With 17.0 I was starring at the "switch alt modus"-button and had no idea what it means. I once turned it on and forgot about it....