This module implements a SAX filter which adds line-numbers and
column-numbers to errors generated by SAX handlers futher down the
pipeline. I wrote this module so that XML::Validator::Schema could
blame the correct line of XML for validation failures.

NOTE: This module requires a SAX parser which correctly supports the
set_document_locator() call. At present there is just one,
XML::SAX::ExpatXS. If you`ve got a number of XML::SAX parsers
installed and you want to make sure XML::SAX::ExpatXS is used, do
this:

$XML::SAX::ParserPackage = 'XML::SAX::ExpatXS';

Author: Sam Tregar