Issue162

Per @betehess' request; the Jena & Sesame DieselOntologyGraphConstructTests currently fail but for different reasons.
That's your problem right there. If you serialise a graph to make it work with a base URI, then you will get a serialisation with an implicit base. If you then move the file ( i.e change the base ) then you will have different triples. In this case your original graph was serialised with `ex1` as base leaving you with 
```
<> a <http://www.w3.org/2002/07/owl#Ontology> .
```
if you then de-serialise this with `ex2` as base then that will give you 

```
<http://example.org/o2>  a <http://www.w3.org/2002/07/owl#Ontology> .
```

and that won't contain `t2`