Improve the validate-xref script. The script currently wraps the xref contents in a <div> element before it passes it to the validator. The actual xref generated by list.jsp wraps it in <div><pre>...</pre></div>. Make the script do the same. This removes some false positives, where the xref starts by closing the <pre> tag and ends by opening a new one. It also makes the script detect more errors, where the xref uses tags not allowed inside a <pre> element.

Add a script that validates generated xref files. The script checks if they contain valid XHTML 1.0 data.