fix bugs in docs

src/site/docs/library-tour/index.markdown

 ---
 layout: default
 title: "A Tour of the Dart Libraries"
 description: "Learn how to use each major Dart library feature."
 has-permalinks: true
 ---
 
 # {{ page.title }}
 
 Welcome to the Dart library tour!
@@ skipping 844 matching lines @@
 
 Sometimes your algorithm needs to initiate many asynchronous methods
 and wait for each one to complete before continuing. Use the Futures class
 to manage multiple Futures and wait for them all to complete.
 
 {% highlight dart %}
 Future deleteDone = deleteLotsOfFiles();
 Future copyDone = copyLotsOfFiles();
 Future checksumDone = checksumLotsOfOtherFiles();
 
-Futures.join([deleteDone, copyDone, checksumDone]).then(() {
+Futures.wait([deleteDone, copyDone, checksumDone]).then((List values) {
   print('Done with all the long steps');
 });
 {% endhighlight %}
 
 #### More information
 
 Refer to the API docs for
 [Future](http://api.dartlang.org/dart_core/Future.html),
 [Futures](http://api.dartlang.org/dart_core/Futures.html), and
 [Completer](http://api.dartlang.org/dart_core/Completer.html)
@@ skipping 804 matching lines @@
   assert(base64 ==
     "iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38G"
     "IAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==");
 }
 {% endhighlight %}
 
 [Back to contents.](#toc)
 {:.up-to-toc}