Clean up examples directory

sky/examples/stocks/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';
 
@@ skipping 10 matching lines @@
   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);
   }
 }