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/preference/MessageArea.java
*/
	public void setBackground(Color bg) {
		super.setBackground(bg);
		messageField.getLayoutControl().setBackground(bg);
		messageField.getControl().setBackground(bg);
		container.setBackground(bg);
	}
	/**
	 * Sets the text in the decorated field which will be displayed
	 * in the message area.
	 * 
	 * @param text the text to be displayed in the message area
	 * 
	 * @see org.eclipse.swt.widgets.Text#setText(String string)
	 */
	public void setText(String text) {
		((Text) messageField.getControl()).setText(text);
	}
	/**
	 * Adds an image to decorated field to be shown in the message area.
	 * 
	 * @param image desired image to be shown in the MessageArea
	 */
	public void setImage(Image image) {
		FieldDecorationRegistry registry = FieldDecorationRegistry.getDefault();
		registry.registerFieldDecoration("errorImage", "Error", image);  
		messageField.addFieldDecoration(registry.getFieldDecoration("errorImage"), 
										SWT.LEFT | SWT.TOP, false);
	}
	/**