Extend navigation keys in completion list.

It came to my attention that nothing happens if I hit Home/End when being in the completion list. I'd expect to jump to the first or last item in the list.

Also, quite nice would be to cycle through the list when being on the first or last item and then pressing the up or down arrow to get to the other end of the list.

I haven't found anything on this topic in the Documentation so I guess there's currently no property to change this behavior.