Get rid of all the library tags.

lib/yaml.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 yaml;
-
 import 'src/loader.dart';
 import 'src/style.dart';
 import 'src/yaml_document.dart';
 import 'src/yaml_exception.dart';
 import 'src/yaml_node.dart';
 
 export 'src/style.dart';
 export 'src/utils.dart' show YamlWarningCallback, yamlWarningCallback;
 export 'src/yaml_document.dart';
 export 'src/yaml_exception.dart';
@@ skipping 88 matching lines @@
 
   var documents = <YamlDocument>[];
   var document = loader.load();
   while (document != null) {
     documents.add(document);
     document = loader.load();
   }
 
   return documents;
 }