Get rid of all the library tags.

lib/src/usage.dart

 // Copyright (c) 2013, 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 args.src.usage;
-
 import 'dart:math';
 
 import '../args.dart';
 
 /// Takes an [ArgParser] and generates a string of usage (i.e. help) text for
 /// its defined options.
 ///
 /// Internally, it works like a tabular printer. The output is divided into
 /// three horizontal columns, like so:
 ///
@@ skipping 227 matching lines @@
 String padRight(String source, int length) {
   final result = new StringBuffer();
   result.write(source);
 
   while (result.length < length) {
     result.write(' ');
   }
 
   return result.toString();
 }