Make sure that key presses are handled in KItemListController

Make sure that key presses are handled in KItemListController

Key press events are forwarded from KItemListContainer to
KItemListController. Right now, only the 'Home' and 'End' keys
are handled (arrow keys require some more work because their action
depends on the view mode).
Note:
1. Before key presses are handled, the view has to be clicked with
   the mouse. It seems that the view does not have the keyboard
   focus initially.
2. The view does not scroll to the new current item yet.