Bug 114615 [Markers] No feedback for 'Completed' tasks
There's not longer any 'check box' indicator on the Tasks View so clients can't determine whether a task has been completed or not... This is a regression...
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/TableView.java
*/
	public void init(IViewSite site, IMemento memento) throws PartInitException {
		super.init(site, memento);
		this.memento = memento;
	}
	/**
	 * 
	 */
	abstract protected void viewerSelectionChanged(
			IStructuredSelection selection);
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.part.WorkbenchPart#createPartControl(org.eclipse.swt.widgets.Composite)
	 */
	public void createPartControl(Composite parent) {
		parent.setLayout(new FillLayout());
		viewer = new TreeViewer(createTree(parent));
		createColumns(viewer.getTree());
		contentProvider = new MarkerTreeContentProvider(getSite());
		viewer.setContentProvider(contentProvider);
		viewer.setLabelProvider(new TableViewLabelProvider(getVisibleFields()));
		viewer.addSelectionChangedListener(new ISelectionChangedListener() {
			public void selectionChanged(SelectionChangedEvent event) {
				IStructuredSelection selection = (IStructuredSelection) event
						.getSelection();
				viewerSelectionChanged(selection);
			}
		});
		viewer.setSorter(buildSorter());