Roll Observatory packages and add a roll script

packages/intl/lib/number_symbols.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.
 library number_symbols;
 
 /**
  * This holds onto information about how a particular locale formats numbers. It
  * contains strings for things like the decimal separator, digit to use for "0"
  * and infinity. We expect the data for instances to be generated out of ICU
  * or a similar reference source.
@@ skipping 17 matching lines @@
       DEF_CURRENCY_CODE;
 
   const NumberSymbols({this.NAME, this.DECIMAL_SEP, this.GROUP_SEP,
       this.PERCENT, this.ZERO_DIGIT, this.PLUS_SIGN, this.MINUS_SIGN,
       this.EXP_SYMBOL, this.PERMILL, this.INFINITY, this.NAN,
       this.DECIMAL_PATTERN, this.SCIENTIFIC_PATTERN, this.PERCENT_PATTERN,
       this.CURRENCY_PATTERN, this.DEF_CURRENCY_CODE});
 
   toString() => NAME;
 }