Roll Observatory packages and add a roll script

packages/analyzer/lib/src/generated/incremental_logger.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 engine.incremental_logger;
 
 /**
  * The shared instance of [Logger] used by several incremental resolution
  * classes. It is initialized externally by the Analysis Engine client.
  */
@@ skipping 166 matching lines @@
     _line += new String.fromCharCode(charCode);
   }
 
   @override
   void writeln([Object obj = '']) {
     _line += obj;
     print(_line);
     _line = '';
   }
 }