Bug 151205 [Viewers] Add setFilters() to change multiple filters at once efficiently
When one needs to add more than one filter after every request a refresh command is issued which is not desired an API-Function where the user could control whether the refresh is called or not would be a great performance improvement.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
* that this feature has been enabled. If the element map is disabled, the
	 * widget is found via <code>doFindInputItem</code>.
	 * </p>
	 * 
	 * @param element
	 *            the element
	 * @return the corresponding widgets
	 * 
	 * @since 3.2
	 */
	protected final Widget[] findItems(Object element) {
		Widget result = doFindInputItem(element);
		if (result != null) {
			return new Widget[] { result };
		}
		
		if (usingElementMap()) {
			Object widgetOrWidgets = elementMap.get(element);
			if (widgetOrWidgets==null) {
				return NO_WIDGETS;
			} else if (widgetOrWidgets instanceof Widget) {
				return new Widget[] {(Widget) widgetOrWidgets};
			} else {
				return (Widget[])widgetOrWidgets;
			}
		}
		result = doFindItem(element);
		return result == null ? NO_WIDGETS : new Widget[] { result };
	}
	/**