Provide quick access toolbar extra button controller functionality.
Inheritance: LeftDownButtonController, ISourceController, IKeyController, IRibbonKeyTipTarget
        /// <summary>
        /// Initialize a new instance of the ViewDrawRibbonQATExtraButton class.
		/// </summary>
        /// <param name="ribbon">Reference to owning ribbon control.</param>
        /// <param name="needPaint">Delegate for notifying paint requests.</param>
        public ViewDrawRibbonQATExtraButton(KryptonRibbon ribbon,
                                            NeedPaintHandler needPaint)
        {
            Debug.Assert(ribbon != null);

            // Remember incoming references
            _ribbon = ribbon;

            // Create delegate used to process end of click action
            _finishDelegate = new EventHandler(ClickFinished);

            // Attach a controller to this element for the pressing of the button
            QATExtraButtonController controller = new QATExtraButtonController(ribbon, this, needPaint);
            controller.Click += new MouseEventHandler(OnClick);
            MouseController = controller;
            SourceController = controller;
            KeyController = controller;
        }
        /// <summary>
        /// Initialize a new instance of the ViewDrawRibbonQATExtraButton class.
        /// </summary>
        /// <param name="ribbon">Reference to owning ribbon control.</param>
        /// <param name="needPaint">Delegate for notifying paint requests.</param>
        public ViewDrawRibbonQATExtraButton(KryptonRibbon ribbon,
                                            NeedPaintHandler needPaint)
        {
            Debug.Assert(ribbon != null);

            // Remember incoming references
            _ribbon = ribbon;

            // Create delegate used to process end of click action
            _finishDelegate = new EventHandler(ClickFinished);

            // Attach a controller to this element for the pressing of the button
            QATExtraButtonController controller = new QATExtraButtonController(ribbon, this, needPaint);
            controller.Click += new MouseEventHandler(OnClick);
            MouseController = controller;
            SourceController = controller;
            KeyController = controller;
        }