make the history list fully and better controllable via the keyboard

Hi.

The history list should be fully controllable via keyboard.
What already works is, opening it (via the hotkey) and pressing "c" seems to cause "Clear".
PageUp/Down already scrolls the list.

I'd further like to see that pressing numbers (1-9,0) causes the entries of that position be selected.
The numers should correspond to the positions in the _show_ list (i.e. what I have currently selected via PageUp/Down).

E.g. if the total list is:
January
February
March
April
May
June
July
August

but shown are only three, e.g.
January
February
March
I should get:
1: January
2: February
3: March

If I scroll down and shown are:
March
April
May
I should get:
1: March
2: April
3: May

Obviously these number may not be enough, especially when the shown list has more than ten entries.
One way would be to simply not support that, another to use the next row of the keyboard, i.e.:
qwertyuiop (with q=11, w=12, and so on)
but of course one would need to consider different keyboard layouts then, e.g. German keyboards would have
qwertzuiop (z vs. y)

Cheers,
Chris.