This is a small utility that is used to test and validate the
XML output generated by doxygen (when GENERATE_XML = YES). 

It uses the Xerces-C XML parser/validator (see http://xml.apache.org) 
and expects the environment variable XERCES_ROOT to point to the root
of the Xerces package.

Currently is reads an XML file, validates it, and prints the class
hierarchy contained in it.