Consolidation of Duplicated Tests

[HeikoKlare]

Some tests have been duplicated for different usage contexts. This applied to the following tests:

• PCM-UML class: Have been duplicated for the mappings tests in *.pcmumlclass.mappings.tests and the transitive change tests in transitivechange.tests.
• UML-Java: Have been duplicated for the transitive change tests in *.transitivechange.tests.

The tests especially differ in the required user interactions and some of them also check the further models that are generated in the case of transitive change propagation (and maybe some further adaptations that I am not aware of). We should figure out how they can be defined once for the bdirectional transformation test, and then reuse them for other scenarios with a way of adapting and extending the predefined user interactions.