[daisy] Hide the query node 'All documents A-Z' for Users

[ddas at lexmark.com]

One would like to hide the query node 'All documents A-Z' for 'role = User'
in the Navigation Tree Editor, to prevent inadvertent deleteting by users
(which probably brings down the site). Only administrators would be allowed
to view it in Navigation Tree Editor.

Help needed.

Thanks

-Dipankar Das