Made Literal.language/datatype into readonly properties. fixes #226
Made Literal.language/datatype into readonly properties.
fixes #226

marma/rdflib,RDFLib/rdflib,RDFLib/rdflib,avorio/rdflib,avorio/rdflib,armandobs14/rdflib,marma/rdflib,armandobs14/rdflib,avorio/rdflib,RDFLib/rdflib,dbs/rdflib,dbs/rdflib,dbs/rdflib,ssssam/rdflib,avorio/rdflib,armandobs14/rdflib,ssssam/rdflib,ssssam/rdflib,yingerj/rdflib,yingerj/rdflib,marma/rdflib,RDFLib/rdflib,yingerj/rdflib,marma/rdflib,ssssam/rdflib,dbs/rdflib,armandobs14/rdflib,yingerj/rdflib