Roll Observatory packages and add a roll script

packages/glob/lib/src/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.
 
 library glob.single_component;
 
 import 'package:path/path.dart' as p;
 import 'package:string_scanner/string_scanner.dart';
 
 import 'ast.dart';
@@ skipping 153 matching lines @@
     }
 
     for (var char in const [']', '(', ')']) {
       if (_scanner.matches(char)) _scanner.error('unexpected "$char"');
     }
     if (!inOptions && _scanner.matches('}')) _scanner.error('unexpected "}"');
 
     return new LiteralNode(buffer.toString(), _context);
   }
 }