Bug 7235 [Contributions] Need dispose() for action delegates
bundles/org.eclipse.jface/src/org/eclipse/jface/action/MenuManager.java
* Disposes of this menu manager and frees all allocated SWT resources.
 * Note that this method does not clean up references between this menu
 * manager and its associated contribution items.
 * Use <code>removeAll</code> for that purpose.
 */
public void dispose() {
	if (menuExist())
		menu.dispose();
	menu = null;
	
	if (menuItem != null) {
		menuItem.dispose();
		menuItem = null;
	}
}
/* (non-Javadoc)
 * Method declared on IContributionItem.
 */
public void fill(Composite parent) {}
/* (non-Javadoc)
 * Method declared on IContributionItem.
 */
public void fill(Menu parent, int index) {
	if (menuItem == null || menuItem.isDisposed()) {
		if (index >= 0)
			menuItem = new MenuItem(parent, SWT.CASCADE, index);
		else
			menuItem = new MenuItem(parent, SWT.CASCADE);
		menuItem.setText(menuText);
		if (!menuExist())