Update pub to use new import syntax.

utils/pub/hosted_source.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.
 
-#library('hosted_source');
+library hosted_source;
 
-#import('dart:io', prefix: 'io');
-#import('dart:json');
-#import('dart:uri');
+import 'dart:io' as io;
+import 'dart:json';
+import 'dart:uri';
 
-#import('io.dart');
-#import('package.dart');
-#import('pubspec.dart');
-#import('source.dart');
-#import('source_registry.dart');
-#import('utils.dart');
-#import('version.dart');
+import 'io.dart';
+import 'package.dart';
+import 'pubspec.dart';
+import 'source.dart';
+import 'source_registry.dart';
+import 'utils.dart';
+import 'version.dart';
 
 /**
  * A package source that installs packages from a package hosting site that
  * uses the same API as pub.dartlang.org.
  */
 class HostedSource extends Source {
   final name = "hosted";
   final shouldCache = true;
 
   /**
@@ skipping 114 matching lines @@
 
     var name = description["name"];
     if (name is! String) {
       throw new FormatException("The 'name' key must have a string value.");
     }
 
     var url = description.containsKey("url") ? description["url"] : defaultUrl;
     return new Pair<String, String>(name, url);
   }
 }