Bug 287103 [CommonNavigator] contentServiceLabelProvider doesn't properly implement overrides
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentServiceLabelProvider.java
* {@inheritDoc}
	 * @see org.eclipse.jface.viewers.IBaseLabelProvider#removeListener(org.eclipse.jface.viewers.ILabelProviderListener)
	 */
	public void removeListener(ILabelProviderListener aListener) {
		removeListenerObject(aListener);
	}
	/**
	 * <p>
	 * Dispose of the content service, if it was created and not supplied.
	 * </p>
	 * <p>
	 * <b>If a client uses this class outside of the framework of {@link CommonViewer}, this method
	 * must be called when finished. </b>
	 * </p>
	 * 
	 * {@inheritDoc}
	 * @see org.eclipse.jface.viewers.IBaseLabelProvider#dispose()
	 */
	public void dispose() {
		if (isContentServiceSelfManaged) {
			contentService.dispose();
		}
	}
	
	/**
     * Fires a label provider changed event to all registered listeners
     * Only listeners registered at the time this method is called are notified.
     *
     * @param event a label provider changed event
     *