Replace bootstrap logic with 'boot.js', use 'component/dart' mime-type and add

pkg/polymer/test/property_change_test.html

Index: pkg/polymer/test/property_change_test.html
diff --git a/pkg/polymer/test/property_change_test.html b/pkg/polymer/test/property_change_test.html
index 25251d39a8f8c3518f94e41710a39b1a41bae49f..7b7867869cb73f1f9347594b803be361aacb5108 100644
--- a/pkg/polymer/test/property_change_test.html
+++ b/pkg/polymer/test/property_change_test.html
@@ -15,6 +15,7 @@ BSD-style license that can be found in the LICENSE file.
     <x-test id="test"></x-test>
 
     <polymer-element name="x-test"><template></template></polymer-element>
-    <script type="application/dart" src="property_change_test.dart"></script>
+    <script type="application/dart;component=1"
+            src="property_change_test.dart"></script>
   </body>
 </html>