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
* boolean.
     * @param visible If <code>true</code> make the image visible, if
     * not then make it not visible.
     */
    private void setImageLabelVisible(boolean visible) {
        messageImageLabel.setVisible(visible);
        leftFillerLabel.setVisible(visible);
    }
    /**
     * Reset the attachment of the workArea to now attach to top as the top
     * control.
     * 
     * @param top
     */
    private void resetWorkAreaAttachments(Control top) {
        FormData childData = new FormData();
        childData.top = new FormAttachment(top);
        childData.right = new FormAttachment(100, 0);
        childData.left = new FormAttachment(0, 0);
        childData.bottom = new FormAttachment(100, 0);
        workArea.setLayoutData(childData);
    }
    
    private void setWarningMessage(String newMessage) {
        
        if (warningMessage == null ? newMessage == null : warningMessage
                .equals(newMessage)) {
			return;
		}
        warningMessage = newMessage;