Remove unused Effen/widgets component

sky/examples/fn/widgets/item.dart

-library item;
-
-import '../../../framework/fn.dart';
-import 'dart:sky' as sky;
-import 'widgets.dart';
-
-enum Color { RED, GREEN }
-
-class Item extends Component {
-
-  String label;
-
-  Color _color = Color.GREEN;
-
-  Item({ Object key, this.label }) : super(key: key);
-
-  Node render() {
-    return new Container(
-      children: [
-        new Radio(
-          onChanged: changed,
-          value: Color.GREEN,
-          groupValue: _color
-        ),
-        new Radio(
-          onChanged: changed,
-          value: Color.RED,
-          groupValue: _color
-        ),
-
-        new Text("$label: ${Color.values[_color.index]}")
-      ]
-    );
-  }
-
-  void changed(Object value) {
-    setState(() {
-      _color = value;
-    });
-  }
-}