Clerezza refactoring

[Reto Gmür]

Hi Hasan,

Thanks for the good conversation today.

I was thinking on how the discussed replacement of TcManager with DataSet could 
look like. I think it would be nice for code like this to work:

        Graph g = new SimpleGraph();
        g.addTriple(s, p, o); //new shortcut method for add(new 
TripleImpl(s,p,o));
        BlankNodeOrIRI graphName = new IRI("http://example.org/g2";);
        DataSet ds = new 
DataSetBuilder().setDefaultGraph(g).addNamedGraph(graphName, g2).build();
        ResultSet rs = ds.querySelect("SELECT ....");

I'm looking forward to a simplified and documented clerezza.

Cheers,
Reto