EZ_GetFancyListBoxSelection returns the selected item(s)
in a fancy listbox widget. If no selection has been made, it return NULL.
Visually, the selected node is displayed with a flashing border.
There are two selection mode in a fancy listbox. In row mode, a row
is selected at a time. A row usually consists of several items. In
this case, EZ_GetFancyListBoxSelection returns an array of
items. In item mode, an item is selected a time.
EZ_GetFancyListBoxSelection returns an array (not NULL
terminated) consists of just item.