add tests for initBindings with/without Variable and leading '?'
add tests for initBindings with/without Variable and leading '?'

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