Roll Observatory packages and add a roll script

packages/intl/lib/src/icu_parser.dart

 // Copyright (c) 2014, 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.
 
 /**
  * Contains a parser for ICU format plural/gender/select format for localized
  * messages. See extract_to_arb.dart and make_hardcoded_translation.dart.
  */
 library icu_parser;
 
@@ skipping 88 matching lines @@
 
   get stuff => (pluralOrGenderOrSelect | empty)
       .map((chunk) => Message.from(chunk, null));
 
   IcuParser() {
     // There is a cycle here, so we need the explicit set to avoid
     // infinite recursion.
     interiorText.set(contents.plus() | empty);
   }
 }