[docbook] Surpressing TOC entries for online Help

[<u.methner@sympatico.ca>]

I'm trying to create a TOC for HTMLHelp, but I don't
want to show all the section headings. I id'd my
section 1's and added the command 
<xsl:template match="sect1[@role='NotInToc']" mode="toc"/>
to my custom template, but it did not do the trick.