Bug 263207 [CommonNavigator] Improve DnD tracing and add DnD test suite
There are no DnD tests for the Common Navigator. Also, the CNF has many test utility classes (basically stolen from JDT), these should be moved into a lower level area, and it looks like org.eclipse.ui.test.harness is a good place. (Perhaps we can get the JDT to use these identical versions as well so there is only one copy that everyone uses). Finally, the DnD tracing needs to be improved to show more information and show it more concisely.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonDragAdapter.java
* Provides an implementation of {@link DragSourceAdapter} which uses the
 * extensions provided by the associated {@link INavigatorContentService}.
 * 
 * <p>
 * Clients should not need to create an instance of this class unless they are
 * creating their own custom viewer. Otherwise, {@link CommonViewer} configures
 * its drag adapter automatically.
 * </p> 
 * 
 * @see INavigatorDnDService
 * @see CommonDragAdapterAssistant
 * @see CommonDropAdapter
 * @see CommonDropAdapterAssistant
 * @see CommonViewer
 * @since 3.2
 * 
 */
public final class CommonDragAdapter extends DragSourceAdapter {
	private final INavigatorContentService contentService;
	private final ISelectionProvider provider;
	/**
	 * Create a DragAdapter that drives the configuration of the drag data.
	 * 
	 * @param aContentService
	 *            The content service this Drag Adapter is associated with
	 * @param aProvider
	 *            The provider that can give the current selection from the
	 *            appropriate viewer.
	 */
	public CommonDragAdapter(INavigatorContentService aContentService,