merged back session bnode test to trunk
merged back session bnode test to trunk

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