CMenu with channel registry enhancements

A uPortal channel for version 2.1 or later. Can present a
collapsable / expandable tree of links. Subclass will represent
channel registry as tree of links which add channel to current
layout in place or cause channel to render in focus mode. Updated
to correct memory leak on 12/21/05

Login to Yale portal as demo. Select Demo channels and applications
on the second tab. Use the Available channels tree to add channels
to the layout. Starting in fall 2004 default behavior will change
to instantiate selected channel in focus but not add it to user's
layout.