Signed-off-by: Alexander Diewald <diewald@fortiss.org>

- Delete unused class HistoryStaticImpl that also suffered from this problem

Remove outdated methods that are not used any more. Their referencing methods from deprecated EClasses have been modified to return empty lists.
refs 3201

When using a non-z3 backend (here: the unofficial MOEA backend) that makes a more extensive use of the ExplorationSolution, invalid models can be produced. The reason for this behavior are faulty containment relations since the produced model fragments of the DSE were not contained in any other EObject. Here, it shall be noted that the SuperSets themselves are not intended as containers as of now since they are also used to pass around references to the relevant elements of a DSE.

Furthermore, one warning was produced due to an EAttribute not being set (noticeable on the console).

Technical details:

* getCastedType(...): Used to avoid ugly casting in client code. The DSE language is based on generic IModelElements, whereas the Sets/SuperSets are strict w.r.t. to the types to provide guarantess for the DSE I/O.
* The ExplorationSpecification now contains the the map of input parameters passed to the DSE (Tracing), but not its elements (!).
* ExplorationSolution: 
* * Contains the returned SuperSetMap.
* * Added a "pool" for SuperSets: They are accessible via the SuperSetMap.
* * Added a element "pool" for the generated elements referenced by the returned SuperSets.
* DSMLModelElementFactory: Creating Sets now requires a reference to the SuperSet (reduced code redundancy; can be used for robustness checking later).
* Adapt to the meta-model changes when using SuperSets/Sets (esp in the smt plugin).
refs 3353

* Change the MM accordingly.
* Introduce static helper methods to implement the getters/setters of the affected maps: Runtime exceptions are thrown on mismatching types.
* Add a migrator to set the DSESuperSet types of old models.
* Adjust the factory methods.
refs 3289

* Modify (Super)Sets to use a generic that denotes the types of elements within a set. Thereby, it is ensured that only elements of this kind are contained/referenced in a specific set.
* Introduce a SuperSetMap that allows to associate the types of elements of supersets with superset instances.
* Use the SuperSetMap as the main entity to pass model elements from the DSE Project to backends.
* Add the ComponentToTaskAllocationTable to the DSESuperSet and the DSE model element: This is the new way to identify which Tasks belong to which Component.
refs 2939

refs 3194

refs 3177