Prolog operator: Added File Operator
Prolog operator: Query can handle string results
Prolog operator: Query can handle double/float
Prolog operator: Prolog lists get correctly trans.
Prolog operator: rename
Prolog operator: Pro-result Terms are translated...

* Prolog result Terms are translated correctly, recursion works
* result lists are translated to products
Merge branch 'prolog1' of https://github.com/opennars/opennars into prolog1