pkg/docgen: sort output files

pkg/docgen/bin/docgen.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.
 
 import 'dart:io';
 
 import 'package:args/args.dart';
 import 'package:logging/logging.dart';
 import 'package:path/path.dart' as path;
 
+// Must use relative paths because library imports mirrors via relative paths
 import '../lib/docgen.dart';
 
 /**
  * Analyzes Dart files and generates a representation of included libraries,
  * classes, and members.
  */
 void main(List<String> arguments) {
   var options = _initArgParser().parse(arguments);
   var files = options.rest.map(path.normalize).toList();
   if (files.isEmpty) _printHelpAndExit();
@@ skipping 128 matching lines @@
       defaultsTo: null);
   parser.addOption('start-page',
       help: 'By default the viewer will start at the SDK introduction page. '
         'To start at some other page, e.g. for a package, provide the name '
         'of the package in this argument, e.g. --start-page=intl will make '
         'the start page of the viewer be the intl package.',
         defaultsTo: null);
 
   return parser;
 }