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
* org.eclipse.ui.internal.navigator.INavigatorContentService#addListener
	 * (org
	 * .eclipse.ui.internal.navigator.extensions.INavigatorContentServiceListener
	 * )
	 */
	public void addListener(INavigatorContentServiceListener aListener) {
		listeners.add(aListener);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.navigator.INavigatorContentService#getFilterService()
	 */
	public INavigatorFilterService getFilterService() {
		if (navigatorFilterService == null) {
			navigatorFilterService = new NavigatorFilterService(this);
		}
		return navigatorFilterService;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.navigator.INavigatorContentService#getFilterService()
	 */
	public INavigatorSorterService getSorterService() {
		if (navigatorSorterService == null) {
			navigatorSorterService = new NavigatorSorterService(this);
			assistant.addListener(navigatorSorterService);
		}
		return navigatorSorterService;