replace cmp with sensible use of > < for py3 compat
replace cmp with sensible use of > < for py3 compat

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