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/extensions/LinkHelperManager.java
*            Helpers are filtered by contentExtension elements in
	 *            viewerContentBindings.
	 * @return An array of <i>visible</i> and <i>enabled</i> Link Helpers or
	 *         an empty array.
	 */
	public LinkHelperDescriptor[] getLinkHelpersFor(
			Object anObject,
			INavigatorContentService aContentService) {
		List helpersList = new ArrayList();
		LinkHelperDescriptor descriptor = null;
		for (Iterator itr = getDescriptors().iterator(); itr.hasNext();) {
			descriptor = (LinkHelperDescriptor) itr.next();
			if (aContentService.isVisible(descriptor.getId())
					&& descriptor.isEnabledFor(anObject)) {
				helpersList.add(descriptor);
			}
		}
		if (helpersList.size() == 0) {
			return NO_DESCRIPTORS;
		}
		return (LinkHelperDescriptor[]) helpersList
				.toArray(new LinkHelperDescriptor[helpersList.size()]);
	}
	/**
	 * Return the link helper descriptors for a given selection and content
	 * service.
	 * 
	 * @param anInput
	 *            The input of the active viewer.
	 * @param aContentService