navtree operates similarly to the sitetree tag, but displays only a
subset of all the site's nodes; it will map all of the top-level nodes of the
site, the parent nodes of the current page, their direct children, and the
current page plus it's children up to depth depth. The effect is similar to
a tree-view-based file browser, like Windows Explorer.
This differs from the sitetree tag in that sitetree does not support
displaying the current page's children.
Display of each page's entry in the tree is performed by expanding one of the 5
template content items named in the tag's attributes: closednode,
opennode, thisnode, thisleaf or leaf. See the sitemap tag
documentation for more details on how to use these (note however that the
is_node variable is not available for sitetrees).
A content item which is evaluated to display an ''open'' node, one which is on
the path to the current page. As for the sitemap tag's node attribute,
this content item must include a reference to the list variable, which will
contain all the entries for the pages beneath it in the hierarchy.
A content item which is evaluated to display an ''open'' root node. It
defaults to opennode if not specified. It may be used to generate
''multirooted'' tree (a forest). In that case you should create a dummy
root content (it upsets sitemap code if you dont have one single root) and
create rootnode template to output only the list with apropriate