* Fix 'line_nubers' in LibXML.pm (with a test).

* Fix the 'suppress_warnings' similarly to https://rt.cpan.org/Ticket/Display.html?id=53270 .

- add a flag to disable touching the I/O callbacks (as requested by
  thread users on xml@gnome.org)

- apply user-data patch (changes the proxy node data structure)


