Updating the samples page to reflect the examples that have been retired.

src/site/samples/multi_touch/example/index.css

-/*
-Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-for details. All rights reserved. Use of this source code is governed by a
-BSD-style license that can be found in the LICENSE file.
-*/
-
-body,html {                                                                      
-    height: 100%;                                                                
-    margin: 0;                                                                   
-    padding: 0;                                                                  
-    color: black;                                                                
-}                                                                                
-                                                                                 
-#container {                                                                     
-    width: 100%;                                                                 
-    height: 100%;                                                                
-    overflow: auto;                                                              
-}                                                                                
-                                                                                 
-#example {                                                                       
-    vertical-align: top;                                                         
-    display: block;                                                              
-    margin: 0;                                                                   
-    overflow: auto;                                                              
-}