Remove library tags, they aren't needed

lib/src/codegen/html_codegen.dart

 // Copyright (c) 2015, 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 dev_compiler.src.codegen.html_codegen;
-
 import 'package:html/dom.dart';
 import 'package:html/parser.dart' show parseFragment;
 import 'package:logging/logging.dart' show Logger;
 import 'package:path/path.dart' as path;
 
 import '../compiler.dart' show AbstractCompiler;
 import '../server/dependency_graph.dart';
 import '../utils.dart' show colorOf, resourceOutputPath;
 
 /// Emits an entry point HTML file corresponding to [inputFile] that can load
@@ skipping 109 matching lines @@
 
 /// Convert the outputPath to include the hash in it. This function is the
 /// reverse of what the server does to determine whether a request needs to have
 /// cache headers added to it.
 _addHash(String outPath, String hash) {
   // (the ____ prefix makes it look better in the web inspector)
   return '$outPath?____cached=$hash';
 }
 
 final _log = new Logger('dev_compiler.src.codegen.html_codegen');