Merge branch 'release/2.3.1'

de.prob.standalone/src/de/prob/standalone/Application.java

...e/src/de/prob/standalone/ApplicationActionBarAdvisor.java

...e/src/de/prob/standalone/ApplicationWorkbenchAdvisor.java

...de/prob/standalone/ApplicationWorkbenchWindowAdvisor.java

...ob.standalone/src/de/prob/standalone/OpenFileCommand.java

.../src/de/prob/standalone/actions/OpenEventBFileAction.java

...dalone/src/de/prob/standalone/actions/OpenFileAction.java

...b/standalone/handler/StartClassicalBAnimationHandler.java

...src/de/prob/standalone/internal/AnimationPerspective.java

...e/prob/standalone/internal/ClassicalBLanguageService.java

...rob/standalone/internal/ProBNavigatorContentProvider.java

.../prob/standalone/internal/ProBNavigatorLabelProvider.java

...rob/standalone/internal/VisualizationEditPerspective.java

...prob/standalone/internal/VisualizationRunPerspective.java

...src/de/prob/standalone/presentation/AbstractClosable.java

...one/src/de/prob/standalone/presentation/Presentation.java

.../de/prob/standalone/presentation/PresentationFactory.java

...b.standalone/src/de/prob/standalone/presentation/Tab.java

...one/src/de/prob/standalone/presentation/TabContainer.java

...standalone/src/de/prob/standalone/presentation/Title.java