Change intl to use new pub layout

pkg/intl/lib/intl_helpers.dart

Index: pkg/intl/lib/intl_helpers.dart
===================================================================
--- pkg/intl/lib/intl_helpers.dart	(revision 12515)
+++ pkg/intl/lib/intl_helpers.dart	(working copy)
@@ -1,43 +0,0 @@
-// Copyright (c) 2012, 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.
-
-/**
- * A library for general helper code associated with the intl library
- * rather than confined to specific parts of it.
- */
-
-#library("intl_helpers");
-
-/**
- * This is used as a marker for a locale data map that hasn't been initialized,
- * and will throw an exception on any usage.
- */
-class UninitializedLocaleData {
-  final String message;
-  const UninitializedLocaleData(this.message);
-
-  operator [](String key) {
-    _throwException();
-  }
-  List getKeys() => _throwException();
-  bool containsKey(String key) => _throwException();
-
-  _throwException() {
-    throw new LocaleDataException("Locale data has not been initialized"
-        ", call $message.");
-  }
-}
-
-class LocaleDataException implements Exception {
-  final String message;
-  LocaleDataException(this.message);
-  toString() => "LocaleDataException: $message";
-}
-
-/**
- *  An abstract superclass for data readers to keep the type system happy.
- */
-abstract class LocaleDataReader {
-  abstract Future read(String locale);
-}