Bug 139986 [CommonNavigator] Convert catch(Error/Throwable) to SafeRunner
In several places the CN framework uses catch(Error/Throwable) to ensure that code does not bring the framework down. Change these to use SafeRunner.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentService.java
private ITreeContentProvider contentProvider;
	/*
	 * Used when providing objects to the CommonViewer by the contentProvider
	 * to record the object/description associations which are when stored
	 * in the Tree associated with the viewer.
	 */
	private Map contributionMemory;
	private Map contributionMemoryFirstClass;
	
	private ILabelProvider labelProvider;
	private final VisibilityAssistant assistant;
	private NavigatorFilterService navigatorFilterService;
	private NavigatorSorterService navigatorSorterService;
	private INavigatorPipelineService navigatorPipelineService;
	private INavigatorDnDService navigatorDnDService;
	private INavigatorActivationService navigatorActivationService;
	private NavigatorSaveablesService navigatorSaveablesService;
	private NavigatorExtensionStateService navigatorExtensionStateService;
	private IDescriptionProvider descriptionProvider;
	private boolean contentProviderInitialized;
	private boolean labelProviderInitialized;
	private boolean isDisposed;
	
	/**
	 * @param aViewerId
	 *            The viewer id for this content service; normally from the
	 *            <b>org.eclipse.ui.views</b> extension.
	 */
	public NavigatorContentService(String aViewerId) {
		super();