Get rid of #source in pub.

utils/pub/io.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.
 
 /**
  * Helper functionality to make working with IO easier.
  */
-#library('pub_io');
+#library('io');
 
 #import('dart:io');
 
 /** Gets the current working directory. */
 String get workingDir() => new File('.').fullPathSync();
 
 /**
  * Prints the given string to `stderr` on its own line.
  */
 void printError(value) {
@@ skipping 363 matching lines @@
 }
 
 /**
  * Gets a [Directory] for [entry], which can either already be one, or be a
  * [String].
  */
 Directory _getDirectory(entry) {
   if (entry is Directory) return entry;
   return new Directory(entry);
 }