Bug 218360 [Servicability] Fix places that pop up message dialogues under ISafeRunnable
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
/**
	 * Indentifier for the error image
	 */
	public static final String PREF_DLG_IMG_TITLE_ERROR = DLG_IMG_MESSAGE_ERROR;
	/**
	 * Title area fields
	 */
	public static final String PREF_DLG_TITLE_IMG = "preference_dialog_title_image"; 
	/**
	 * Return code used when dialog failed
	 */
	protected static final int FAILED = 2;
	
	/**
	 * The current preference page, or <code>null</code> if there is none.
	 */
	private IPreferencePage currentPage;
	private DialogMessageArea messageArea;
	private Point lastShellSize;
	private IPreferenceNode lastSuccessfulNode;
	/**
	 * The minimum page size; 400 by 400 by default.
	 * 
	 * @see #setMinimumPageSize(Point)
	 */
	private Point minimumPageSize = new Point(400, 400);
	/**
	 * The OK button.
	 */
	private Button okButton;