Bug 182661 Cross Tab: Need to support "New Data Cube" from menu bar
Please look at the UI mockup as reference to support "New Data Cube" on dropdown menu from Menu bar.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/DesignerActionBarContributor.java
* @see org.eclipse.ui.part.EditorActionBarContributor#contributeToMenu(IMenuManager)
	 */
	public void contributeToMenu( IMenuManager menubar )
	{
		super.contributeToMenu( menubar );
		updateEditMenu( menubar );
		
		MenuManager insertMenu = new MenuManager( Messages.getString( "DesignerActionBarContributor.menu.insert" ), M_INSERT ); 
		contributeActionsToMenu( insertMenu, getInsertElementActions( ) );
		insertMenu.add( new Separator( ) );
		insertMenu.add( getAction( ImportLibraryAction.ID ) );
		menubar.insertAfter( IWorkbenchActionConstants.M_EDIT, insertMenu );
		
		MenuManager elementMenu = new MenuManager( Messages.getString( "DesignerActionBarContributor.menu.element" ), M_ELEMENT ); 
		contributeActionsToMenu( elementMenu, elementActions );
		MenuManager insertGroupMenu = new MenuManager( Messages.getString( "DesignerActionBarContributor.element.group" ), InsertGroupMenuAction.ID ); 
		insertGroupMenu.add( NoneAction.getInstance( ) );
		insertGroupMenu.addMenuListener( new IMenuListener( ) {
			public void menuAboutToShow( IMenuManager manager )
			{
				updateInsertGroupMenu( InsertGroupMenuAction.ID, manager );
			}
		} );
		elementMenu.add( insertGroupMenu );
		MenuManager editGroupMenu = new MenuManager( Messages.getString( "DesignerActionBarContributor.menu.element-EditGroup" ) ); 
		editGroupMenu.add( NoneAction.getInstance( ) );
		editGroupMenu.addMenuListener( new IMenuListener( ) {
			public void menuAboutToShow( IMenuManager manager )
			{
				updateDynamicItems( EditGroupMenuAction.ID, manager );