* [JSON_TO_RDF,SC,FIX] Some polishing on recent rewrite of this module.
* [XML_DATATYPES,NEW] Distinguish between XML 1.0 and XML 1.1 characters.
* [XSD_STRING,FIX] Use the character production from XML 1.1 (used to be XML 1.0), allowing all literal values to now be asserted as values of XSD string (conforming to RDF 1.1).