Exploration: DSE project MM improvements & DSE Backend Unification

=================
| Exploration

exploration.ecore
=================
- ExplorationSpecification
  - targets: non-contained (Migrator!)
  - Add superSet reference to pass required SuperSets to the DSE backend.
- Remove ExplorationSolution interface: No Migration needed.
- Rename ExplorationSolutionSet --> ExplorationSolution
  - Deprecated inputModelAdapter: No migration needed, only used in MOEA.
  - Renaming: targetSpecification --> explorationSpec
    - targetSpecification marked @deprecated
    - No mirgator needed: Class was not used in previous stable releases.
- Add EClass SuperSetMap: Relates types of elements to SuperSets
  - solution: EJavaClassToSuperSetMap (containment!)
- Add EClass EJavaClassToSuperSetMap: internal map of "SuperSetMap"
  - key: Class
  - Value: SuperSet (NO containment!)
- ExplorationSolution
  - Renamed solutionModelMap -> solutionSets
    (Type EJavaClassToEJavaObjectMap -> EJavaClassToSuperSetMap)
  - Adjust EOperations to modifications in backend map.
- SingleExplorationSolution
  - Add the solution state for single solutions.
  - Adjust EOperations to modifications in backend map.
- Removed EJavaClassToEJavaObjectMap

dseproject.ecore
================
- DSE:
  - Add EReference target: ExplorationTarget (containment)
  - Remove explorationSpecification (Migrator!)
- Add an ExplorationTargetPool that contains all ExplorationTargets of a DSE
  project.
- DSERun:
  - Add EReference explorationSolution (containment)
  - Remove EReference visualization (Migrator!)
  
dsl_v2.ecore
============
- Overwrite the accept method for the Sum expression: Do not return null if the
  associated set is empty, evaluate to Zero, instead.

New Migrators
=============
- DSEExplorationTargetContainmentMigrator
  Migrates the set of explorationTargets to the DSE project
- VisualizationToExpSolutionMigrator:
  Migrates the Visualization data to the ExplorationSolution representation that
  allows a better traceability.
  
Other Business
==============
- Adjust plugin.xml to account for recently removed Objective- and
  ConstraintExpression classes. Now, ExplorationObjective and
  ExplorationConstraint is used.
  
=================
| Exploration.alg

- Adjust the Opt4JBackend to be comply to the new DSE Backend Specification
- The output type detection in the base decoder is more robust.
- The ITaskAdapter temporally references its corresponding component to ease
  the refactoring of the DSE backend interface. This shall not be needed when
  the transformation framework is integrated again.
- Temporally transform the internal solutions to a superset of
  ComponentToExecutionUnitAllocations to create s solution model. Workaround
  until the transformation framework is integrated again.
- Misc adjustment for backend changes.

=================
| Exploration.smt

- Adjust the Z3Backend to be comply to the new DSE Backend Specification
- Base the results of the DeploymentRun2 and SolverRun2 on the
  ExplorationSolution (see above).

================
| Exploration.ui

- Adjust the GUI logic to account for the changed containment relations.
- Update the DSE project import wizard for the Meta-Model changes.
- Move the ExplorationSolutionVisualizationUtils class to the UI plugin (here).
  It is used to transform ExplorationSolutions to a Visualization representation
  (i.e., DataSetCollection).
- Use doubles instead of ints in the SpiderChartUtils. Although not a proper
  solution, this covers more cases... Instead the generic should be reflected.
refs 3273