Bug 261147 [CommonNavigator] Navigator label provider uses inconsistent methods to do the same thing
In NavigatorContentServiceLabelProvider some of the methods use findContentExtensionsWithPossibleChild and others use findRelevantLabelProvider. The latter is better and they should all use that one.
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
     *