removed unused imports and restriction on output formats (it uses whatever rdflib supports).  
removed unused imports and restriction on output formats (it uses whatever rdflib supports).  

git-svn-id: 60eb48102d1ca0c284ab3654bef916b01e1b221b@1078 4f84a9ca-5c3e-0410-8a68-0bdf370325d5

nwebs/rdflib