Bug 26109 [Dialogs] Need a FormData version of the button sizing API
The button sizing API in Dialog assumes the developer wants a GridData. We should promote the FormData version in PathVariablesDialog to Dialog.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/Dialog.java
* @since 2.0
	 */
	public static final String DLG_IMG_MESSAGE_WARNING = "dialog_messasge_warning_image";
	/**
	 * Image registry key for info message image (value <code>"dialog_message_error_image"</code>).
	 * @since 2.0
	 */
	public static final String DLG_IMG_MESSAGE_ERROR = "dialog_message_error_image";
	static {
		ImageRegistry reg = JFaceResources.getImageRegistry();
		reg.put(DLG_IMG_INFO, ImageDescriptor.createFromFile(Dialog.class, "images/inform.gif"));
		reg.put(DLG_IMG_QUESTION, ImageDescriptor.createFromFile(Dialog.class, "images/question.gif"));
		reg.put(DLG_IMG_WARNING, ImageDescriptor.createFromFile(Dialog.class, "images/warning.gif"));
		reg.put(DLG_IMG_ERROR, ImageDescriptor.createFromFile(Dialog.class, "images/error.gif"));
		
		reg.put(DLG_IMG_MESSAGE_INFO, ImageDescriptor.createFromFile(Dialog.class, "images/message_info.gif"));
		reg.put(DLG_IMG_MESSAGE_WARNING, ImageDescriptor.createFromFile(Dialog.class, "images/message_warning.gif"));
		reg.put(DLG_IMG_MESSAGE_ERROR, ImageDescriptor.createFromFile(Dialog.class, "images/message_error.gif"));
	}
	/**
	 * 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.
	 */
	protected Control buttonBar;
	
	/**
	 * Collection of buttons created by the <code>createButton</code> method.