Added working test cases for RDF_MT (also for blank nodes and invalid models).

* [RDF_AXIOM,SC] Added extra conditions to the transitive deductions: objects should be dissimilar.
* [RDF_AXIOM_TEST,SC] Separate module for unit testing RDF_AXIOM.
* [RDF_MT_BUILD,FIX] The model name was not removed during model cleaning.
* [RDF_MT_I,SC] Added determinism for term interpretations that do not involve adding an arbitrary assignment pair.
* [RDF_MT_PRINT,SC] No longer print categories with zero members.
* [RDF_MT_TEST,EXT] Added new test cases.