Clean up examples directory

sky/examples/stocks-fn/lib/stock_list.dart

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'package:sky/framework/animation/scroll_behavior.dart';
-import 'package:sky/framework/components/fixed_height_scrollable.dart';
-import 'package:sky/framework/fn.dart';
-import 'stock_data.dart';
-import 'stock_row.dart';
-
-class Stocklist extends FixedHeightScrollable {
-  String query;
-  List<Stock> stocks;
-
-  Stocklist({
-    Object key,
-    this.stocks,
-    this.query
-  }) : super(key: key, scrollBehavior: new OverscrollBehavior());
-
-  List<Node> buildItems(int start, int count) {
-    return stocks
-      .skip(start)
-      .where((stock) => query == null || stock.symbol.contains(
-          new RegExp(query, caseSensitive: false)))
-      .take(count)
-      .map((stock) => new StockRow(stock: stock))
-      .toList(growable: false);
-  }
-}