Bug 131771 Match animated message behaviour in Preferences
An enhancement should be made to Preferences so that warnings and errors show up in a sliding message area like it they do in TitleAreaDialog.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/TitleAreaDialog.java
*/
    protected Point getInitialSize() {
        Point shellSize = super.getInitialSize();
        return new Point(Math.max(
                convertHorizontalDLUsToPixels(MIN_DIALOG_WIDTH), shellSize.x),
                Math.max(convertVerticalDLUsToPixels(MIN_DIALOG_HEIGHT),
                        shellSize.y));
    }
    /**
     * Retained for backward compatibility.
     * 
     * Returns the title area composite. There is no composite in this
     * implementation so the shell is returned.
     * 
     * @return Composite
     * @deprecated
     */
    protected Composite getTitleArea() {
        return getShell();
    }
    /**
     * Returns the title image label.
     * 
     * @return the title image label
     */
    protected Label getTitleImageLabel() {
        return titleImage;
    }
    /**
     * Display the given error message. The currently displayed message is saved