Bug 299209 [CommonNavigator] Clean up error reporting for pipelined extensions
A catch block was missing for one of them, and the error report does not provide the extension Id that had the problem.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorPipelineService.java
private NavigatorContentService contentService;
	/**
	 * Create a pipeline assistant for the given content service.
	 * 
	 * @param aContentService
	 *            The content service that will drive this pipeline assistant.
	 */
	public NavigatorPipelineService(NavigatorContentService aContentService) {
		contentService = aContentService;
	}
	/**
	 * Intercept attempts to add elements directly to the viewer.
	 * 
	 * <p>