We need to develop a new renderer to display a filearea:
- based on folder_print_tree() in mod/folder/lib.php
- lib/outputrenderers.php and lib/outputcomponents.php
- $OUTPUT->render(new file_tree_viewer($contextid, $area, $itemid)) (See http://moodle.org/mod/cvsadmin/view.php?conversationid=4890#c199918)