
An IconWindow is used as parent for
Icon objects.  The child-icons are
positioned automatically.  IconWindow
comes with methods to arrange the icons
and select or unselect one or all.  As
soon as an icon is being positioned outside
of the IconWindow's shape, a scroll-bar
appears (horizontal, if icon placed right of
the rigth side OR vertical if placed below
the bottom).  The scrolling mechanism 
does not work yet.