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

pkg/polymer/test/entered_view_test.dart

Index: pkg/polymer/test/entered_view_test.dart
diff --git a/pkg/polymer/test/entered_view_test.dart b/pkg/polymer/test/entered_view_test.dart
index 632ea70ccf01792f0b0a43ba5e8a57acb8e2e6ef..afd6b2da2124e82e27708c49d6e2b1624e312740 100644
--- a/pkg/polymer/test/entered_view_test.dart
+++ b/pkg/polymer/test/entered_view_test.dart
@@ -30,9 +30,8 @@ class XInner extends PolymerElement {
   }
 }
 
-main() => initPolymer().run(_tests);
-
-_tests() {
+@initMethod
+main() {
   useHtmlConfiguration();
   Polymer.register('x-inner', XInner);
   Polymer.register('x-outer', XOuter);