Get rid of all the library tags.

lib/shelf_proxy.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 shelf_proxy;
-
 import 'package:http/http.dart' as http;
 import 'package:path/path.dart' as p;
 import 'package:shelf/shelf.dart';
 
 import 'src/utils.dart';
 
 /// A handler that proxies requests to [url].
 ///
 /// To generate the proxy request, this concatenates [url] and [Request.url].
 /// This means that if the handler mounted under `/documentation` and [url] is
@@ skipping 77 matching lines @@
 // TODO(nweiz): use built-in methods for this when http and shelf support them.
 /// Add a header with [name] and [value] to [headers], handling existing headers
 /// gracefully.
 void _addHeader(Map<String, String> headers, String name, String value) {
   if (headers.containsKey(name)) {
     headers[name] += ', $value';
   } else {
     headers[name] = value;
   }
 }