KDirOperator usability improvement [bugfix]

[Aurélien Gâteau]

Rafael Fernández López wrote:

> We also can consider to move a level up on the hierarchy when pressing
> backspace and the focus is on the list view, that would make optional the
> mouse usage on this dialog, and I think some users can benefit from it
> (e.g. visually impaired people unable to use mouse). What do you think ?

In KDE3, the shortcut to move a level up is Alt+Up arrow, maybe you should
use this instead of Backspace.

Aurélien