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/sorters/CommonSorterDescriptor.java
id = ""; 
		}
		IConfigurationElement[] children = element
				.getChildren(TAG_PARENT_EXPRESSION);
		if (children.length == 1) {
			parentExpression = new CustomAndExpression(children[0]);
		}
	}
	/**
	 * 
	 * @return An identifier used to determine whether the sorter is visible.
	 *         May not be unique.
	 */
	public String getId() {
		return id;
	}
 
	/**
	 * 
	 * @param aParent
	 *            An element from the viewer
	 * @return True if and only if this CommonSorter can sort the children of
	 *         the given parent.
	 */
	public boolean isEnabledForParent(Object aParent) {
		if(aParent == null) {
			return false;
		}
		if (parentExpression != null) {
			IEvaluationContext context = NavigatorPlugin.getEvalContext(aParent);