The tabbedpanel widget is primarily an AJAX component, where each tab can either be local content or remote
content (refreshed each time the user selects that tab).
Renders a tree widget with AJAX support.
The "id "attribute is normally specified(recommended), such that it could be looked up using
javascript if necessary.
Renders a tree node within a tree widget with AJAX support.
Either of the following combinations should be used depending on if the tree
is to be constructed dynamically or statically.