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 XERCESCROOT 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.