The no-args org.xml.sax.helpers.XMLReaderFactory.createXMLReader() method fails
(throws a SAXException) unless the org.xml.sax.driver property is set. If this
property is not set, this methoid should not fail. Instead it should fall back
to the standard Xerces parser, probably org.xml.parsers.SAXParser.

This is in accordance with the SAX documentaiton for this class
(http://sax.sourceforge.net/apidoc/org/xml/sax/helpers/XMLReaderFactory.html)
which states:

Note to Distributions bundled with parsers:  You should modify the
implementation of the no-arguments createXMLReader to handle cases where the
external configuration mechanisms aren't set up. That method should do its best
to return a parser when one is in the class path, even when nothing bound its
class name to org.xml.sax.driver so those configuration mechanisms would see it.