Add support of writingData for typeValue and monoid:
- plusSym - timesSym - ... * data/vaucanson.xsd: Here. * include/vaucanson/algebra/implementation/monoid/free_monoid.hh: Since we need to create the monoid before parsing its content, we need to update the representation after its creation. So set_representation should be public (or friendly) * include/vaucanson/xml/builders.hh: Here. * include/vaucanson/xml/builders.hxx: Here. * include/vaucanson/xml/handlers.hh: Here. * include/vaucanson/xml/handlers.hxx: Here. * include/vaucanson/xml/printers.hxx: Here. * include/vaucanson/xml/xmleq.hh: Here. * include/vaucanson/xml/xmleq.hxx: Here.