Bug 143430 [CommonNavigator] CommonNavigator requires initialInput to be Adaptable
I have a root nodes that is not Adaptable and that does not fit well with CommonNavigator.getInitialInput which requires (for no real good reason ?) to be Adaptable. Should this not just be an Object ?
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonNavigator.java
* <p>
	 * Returns the tool tip text for the given element. Used as the tool tip
	 * text for the current frame, and for the view title tooltip.
	 * </p>
	 * @param anElement 
	 * @return the tool tip text
	 * @since 3.4
	 * 
	 */
	public String getFrameToolTipText(Object anElement) {
		if (commonViewer == null)
			return ""; 
		return ((ILabelProvider) commonViewer.getLabelProvider())
					.getText(anElement);
	}
	
	/**
	 * <p>
	 * Note: This method is for internal use only. Clients should not call this
	 * method.
	 * </p>
	 * <p>
	 * This method will be invoked when the DisposeListener is notified of the
	 * disposal of the Eclipse view part.
	 * </p>
	 * 
	 * @see org.eclipse.ui.part.WorkbenchPart#dispose()
	 */
	public void dispose() {
		if (commonManager != null) {