Headers within paragraph level elements

[margaretha]

A few problems including a deadlock, have been occurred in WikiXML to I5 conversion, due to the appearances of headers within paragraph level elements such as <li> or <ref>.

The problematic WikiXML structures come probably due to improper parsing of wikitext to WikiXML by WikiXMLConverter.

Nevertheless, to make WikiI5Converter robuster, we should probably simplify the WikiXML to I5 conversion by simply using xsl:value-of when the situations appear and not further applying templates.