* [XML_TO_RDF,NEW] Complete rewrite, presenting a completely new way of converting an XML file to an RDF graph.
* [XSD_DATATYPE,EXT] xsd_datatype/2 now also works for instantiation (-,-), registering all supported datatypes explicitly.
* [XSD_DATE,EXT] Support for atom values, these are parsed by DCG_DATE.
* [XSD_DECIMAL,EXT] Support for atomic values, these are converted into numbers.