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/MessageArea.java
private int BORDER_MARGIN = IDialogConstants.HORIZONTAL_SPACING/2;
	private DecoratedField messageField;
	private Composite container;
	
	/**
	 * Constructs a new MessageArea with an empty decorated field.
	 * Calls to <code>setText(String text)</code> and <code>setImage(Image image)</code> 
	 * are required in order to fill the message area. 
	 * 
	 * @param parent the parent composite
	 * @param style the SWT style bits
	 */
	public MessageArea(Composite parent, int style) {
		super(parent, style);
		container = new Composite(this, style);
		GridLayout glayout = new GridLayout();
		glayout.numColumns = 2;
		glayout.marginWidth = 0;
		glayout.marginHeight = 0;
		container.setLayout(glayout);
		messageField = new DecoratedField(container,SWT.READ_ONLY,new TextControlCreator());
		messageField.getLayoutControl().setLayoutData(new GridData(SWT.FILL,SWT.FILL,true,true));
       
		addPaintListener(new PaintListener() {