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

samples/polymer_intl/test/polymer_intl_test.dart

Index: samples/polymer_intl/test/polymer_intl_test.dart
diff --git a/samples/polymer_intl/test/polymer_intl_test.dart b/samples/polymer_intl/test/polymer_intl_test.dart
index 7e82a2f52653ba751f1fda6a3a9bfd4e625ccd52..dc929f6c3947a23a92534ba6212161a3ad3c4a89 100644
--- a/samples/polymer_intl/test/polymer_intl_test.dart
+++ b/samples/polymer_intl/test/polymer_intl_test.dart
@@ -15,8 +15,8 @@ import '../web/localized.dart';
  * A trivial test to get the analyzer plugged into this sample. See
  * searchable_list_test.dart.
  */
+@initMethod
 main() {
-  initPolymer();
   useHtmlConfiguration();
 
   setUp(() => Polymer.onReady);