Bug 57762 [Dialogs] honor the platform button dismissal alignment on Mac and GTK
Button ordering is inverted on these platforms. See Display.getDismissalAlignment() or the equivalent JFace mechansim.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/Dialog.java
* Constants that can be used for specifying the strategy for persisting
	 * dialog bounds.  These constants represent bit masks that can be used
	 * together.
	 *
	 *@since 3.2
	 */
	
	/**
	 * Persist the last location of the dialog.
	 * @since 3.2
	 */
	public static final int DIALOG_PERSISTLOCATION = 0x0001;
	/**
	 * Persist the last known size of the dialog.
	 * @since 3.2
	 */
	public static final int DIALOG_PERSISTSIZE = 0x0002;
	
	/**
	 * The dialog area; <code>null</code> until dialog is layed out.
	 */
	protected Control dialogArea;
	/**
	 * The button bar; <code>null</code> until dialog is layed out.
	 */
	public Control buttonBar;
	
	/**
	 * Collection of buttons created by the <code>createButton</code> method.
	 */