Bug 12116 [Contributions] widgets: MenuManager.setImageDescriptor() method needed
Currently there seems to be no API to assign image to menu item that contains submenu, the only way is to override MenuManager.fill() methods. That seems to be inconsistent.
bundles/org.eclipse.jface/src/org/eclipse/jface/action/MenuManager.java
* The parent contribution manager.
     */
    private IContributionManager parent;
    /**
     * Indicates whether <code>removeAll</code> should be
     * called just before the menu is displayed.
     */
    private boolean removeAllWhenShown = false;
    /**
     * Indicates this item is visible in its manager; <code>true</code> 
     * by default.
     * @since 3.3
     */
    protected boolean visible = true;
    /**
     * Creates a menu manager.  The text and id are <code>null</code>.
     * Typically used for creating a context menu, where it doesn't need to be referred to by id.
     */
    public MenuManager() {
        this(null, null);
    }
    /**
     * Creates a menu manager with the given text. The id of the menu
     * is <code>null</code>.
     * Typically used for creating a sub-menu, where it doesn't need to be referred to by id.
     *
     * @param text the text for the menu, or <code>null</code> if none
     */
    public MenuManager(String text) {
        this(text, null);