Bug 157174 [Viewers] Refactor new Viewer API
We are yet not completely happy with the API and refactor it.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/LabelProvider.java
/**
     * Creates a new label provider.
     */
    public LabelProvider() {
    }
    /* (non-Javadoc)
     * Method declared on IBaseLabelProvider.
     */
    public void addListener(ILabelProviderListener listener) {