Update intl to new import syntax

pkg/intl/lib/src/intl_helpers.dart

 // 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");
+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) {
@@ skipping 32 matching lines @@
 /**
  * Initialize the message lookup mechanism. This is for internal use only.
  * User applications should import `message_lookup_local.dart` and call
  * `initializeMessages`
  */
 void initializeInternalMessageLookup(Function lookupFunction) {
   if (messageLookup is UninitializedLocaleData) {
     messageLookup = lookupFunction();
   }
 }