added native N3/Turtle serialization for Collection instances ( n3 method)
added native N3/Turtle serialization for Collection instances ( n3 method)

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