Practically remove boot.js, adds the initialization from the Dart side of

pkg/polymer/test/events_test.dart

 // Copyright (c) 2013, 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.
 
 library polymer.test.web.events_test;
 
 import 'dart:html';
 import 'package:polymer/polymer.dart';
 import 'package:unittest/html_config.dart';
 import 'package:unittest/unittest.dart';
 
-main() {
+@initMethod _main() {
   useHtmlConfiguration();
 
   setUp(() => Polymer.onReady);
 
   test('host event', () {
     // Note: this test is currently the only event in
     // polymer/test/js/events.js at commit #7936ff8
     var testA = query('#a');
     expect(testA.xtag.clicks, isEmpty);
     testA.click();
     expect(testA.xtag.clicks, ['host click on: test-a (id a)']);
   });
 
   test('local event', () {
     var testB = query('#b');
     expect(testB.xtag.clicks, isEmpty);
     testB.click();
     expect(testB.xtag.clicks, []);
     var b1 = testB.shadowRoot.query('#b-1');
     b1.click();
     expect(testB.xtag.clicks, []);
     var b2 = testB.shadowRoot.query('#b-2');
     b2.click();
     expect(testB.xtag.clicks, ['local click under test-b (id b) on b-2']);
   });
 }