Added a single emptyEnsemble to SliceRepository
Added undefined ConstraintType
Updated Datamodel Wizard to create emptyEnsemble
Updated Graphiti Features to use new EmptyEnsemble
Merge branch 'master' of git@github.com:Delors/Vespucci2.git

Conflicts:
	de.opalproject.vespucci.sliceEditor/src/de/opalproject/vespucci/sliceEditor/features/AddEnsembleFeature.java
Merge branch 'master' of git@github.com:Delors/Vespucci2.git