Update intl to new import syntax

pkg/intl/lib/bidi_formatter.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.
 
+part of intl;
+
 /**
  * Bidi stands for Bi-directional text.
  * According to [Wikipedia](http://en.wikipedia.org/wiki/Bi-directional_text):
  * Bi-directional text is text containing text in both text directionalities,
  * both right-to-left (RTL) and left-to-right (LTR). It generally involves text
  * containing different types of alphabets, but may also refer to boustrophedon,
  * which is changing text directionality in each row.
  *
  * Utility class for formatting display text in a potentially
  * opposite-directionality context without garbling layout issues.
@@ skipping 176 matching lines @@
       if (contextDirection == TextDirection.LTR) {
         return Bidi.LRM;
       } else {
         return Bidi.RLM;
       }
     } else {
       return '';
     }
   }
 }