Removed TutorialDefinition class (replaced by TutorialCompositeStep).

...ooling/kernel/ui/extension/data/TutorialStepUIAtomic.java

...ing/kernel/ui/extension/data/TutorialStepUIComposite.java

.../fortiss/tooling/kernel/ui/internal/NavigatorService.java

...ernel/ui/internal/views/NavigatorTreeContentProvider.java

.../kernel/ui/internal/views/NavigatorTreeContentSorter.java

...s/tooling/kernel/ui/internal/views/NavigatorViewPart.java

...entation/TutorialDefinitionModelElementLabelProvider.java

...ortiss/tooling/kernel/ui/util/TutorialUIServiceUtils.java

...g/fortiss/tooling/kernel/extension/ITutorialProvider.java

...iss/tooling/kernel/extension/data/TutorialAtomicStep.java

.../tooling/kernel/extension/data/TutorialCompositeStep.java

...iss/tooling/kernel/extension/data/TutorialDefinition.java

...rtiss/tooling/kernel/extension/data/TutorialStepBase.java

.../org/fortiss/tooling/kernel/internal/TutorialService.java

.../org/fortiss/tooling/kernel/service/ITutorialService.java

...ing/kernel/service/listener/ITutorialServiceListener.java