Update pub to use new import syntax.

utils/pub/pub.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.
 
 /**
  * The main entrypoint for the pub command line application.
  */
-#library('pub');
+library pub;
 
-#import('../../pkg/args/lib/args.dart');
-#import('dart:io');
-#import('dart:math');
-#import('io.dart');
-#import('command_help.dart');
-#import('command_install.dart');
-#import('command_update.dart');
-#import('command_version.dart');
-#import('entrypoint.dart');
-#import('exit_codes.dart', prefix: 'exit_codes');
-#import('git_source.dart');
-#import('hosted_source.dart');
-#import('package.dart');
-#import('pubspec.dart');
-#import('sdk_source.dart');
-#import('source.dart');
-#import('source_registry.dart');
-#import('system_cache.dart');
-#import('utils.dart');
-#import('version.dart');
+import '../../pkg/args/lib/args.dart';
+import 'dart:io';
+import 'dart:math';
+import 'io.dart';
+import 'command_help.dart';
+import 'command_install.dart';
+import 'command_update.dart';
+import 'command_version.dart';
+import 'entrypoint.dart';
+import 'exit_codes.dart' as exit_codes;
+import 'git_source.dart';
+import 'hosted_source.dart';
+import 'package.dart';
+import 'pubspec.dart';
+import 'sdk_source.dart';
+import 'source.dart';
+import 'source_registry.dart';
+import 'system_cache.dart';
+import 'utils.dart';
+import 'version.dart';
 
 Version get pubVersion => new Version(0, 0, 0);
 
 /**
  * The commands that Pub understands.
  */
 Map<String, PubCommand> get pubCommands => {
   'help': new HelpCommand(),
   'install': new InstallCommand(),
   'update': new UpdateCommand(),
@@ skipping 224 matching lines @@
     if (exception is HttpException || exception is HttpParserException ||
         exception is SocketIOException || exception is PubHttpException) {
       return exit_codes.UNAVAILABLE;
     } else if (exception is FormatException) {
       return exit_codes.DATA;
     } else {
       return 1;
     }
   }
 }