some refactoring and cleanup

...rtiss/tooling/base/ui/action/ModelElementsActionBase.java

...ng/base/ui/compose/ConnectorConnectionCompositorBase.java

...rc/org/fortiss/tooling/base/ui/editor/gef/EditorBase.java

...se/ui/internal/command/GEF2ToolingKernelCommandStack.java

...org/fortiss/tooling/kernel/ui/internal/ActionService.java

...org/fortiss/tooling/kernel/ui/internal/MarkerService.java

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

...rnel/ui/internal/properties/PropertiesAdapterFactory.java

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

org.fortiss.tooling.kernel/trunk/schema/modelElement.exsd

...s.tooling.kernel/trunk/schema/transformationProvider.exsd

...rtiss/tooling/kernel/extension/IConnectionCompositor.java

.../fortiss/tooling/kernel/extension/IConstraintChecker.java

.../fortiss/tooling/kernel/extension/IElementCompositor.java

...rg/fortiss/tooling/kernel/extension/IStorageProvider.java

...iss/tooling/kernel/extension/ITransformationProvider.java

...el/extension/data/ChainTransformationFailedException.java

...tooling/kernel/extension/data/ITransformationContext.java

...ng/kernel/extension/data/TransformationProviderChain.java

.../fortiss/tooling/kernel/internal/CommandStackService.java