Module nextpanel

Multi-pane list similar to the NeXT file-manager

This widget is designed for hierarchical display of data, similar to
what a tree could provide but allows more information to be displayed
at one time (at the cost of more screen real estate).

The NeXTPanel is a set of columns that adds more columns as you delve
deeper into the hierarchy.  The initial view is just a single column
displaying the root of the hierarchy.  Selecting one or more items
causes another column to be displayed to the right of the column
displaying the children of the selected items.  More columns can be
added by selecting items in the new list.

@author: Rob McMullen
@version: 0.1

Changelog:
    0.1:
        * initial release