Delete polymer from the Dart repo

pkg/polymer/lib/init.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 that automatically initializes polymer elements without having to
-/// write a main for your application.
-///
-/// If a polymer application is written entirely with `<polymer-element>` tags
-/// and there is no initialization code that needs to happen before these
-/// elements are created, then, instead of creating your own `main`, you can
-/// simply include a script tag loading this library:
-///
-///    <script type="application/dart">import "package:polymer/init.dart";
-///    </script>
-///
-/// This script tag should be placed after all HTML imports on your page.
-library polymer.init;
-
-import 'package:polymer/polymer.dart';
-
-main() => initPolymer();