Default editor for TutorialSteps working properly.

org.fortiss.tooling.kernel.ui/trunk/plugin.xml

...tiss/tooling/kernel/ui/extension/ITutorialUIProvider.java

...tiss/tooling/kernel/ui/extension/data/TutorialStepUI.java

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

...g/kernel/ui/internal/editor/TutorialStepUIDefaultGUI.java

...oling/kernel/ui/internal/editor/TutorialStepUIEditor.java

...g/fortiss/tooling/kernel/extension/data/TutorialStep.java

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