Fix dartdoc editor integration.

pkg/dartdoc/bin/dartdoc.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.
 
 /**
  * To generate docs for a library, run this script with the path to an
  * entrypoint .dart file, like:
  *
  *     $ dart dartdoc.dart foo.dart
  *
@@ skipping 22 matching lines @@
     ? scriptDir.append('../../../lib/dart2js/')
     : scriptDir.append('../../../');
 
 /**
  * Run this from the `pkg/dartdoc` directory.
  */
 main() {
   final args = new Options().arguments;
 
   final dartdoc = new Dartdoc();
+  dartdoc.dartdocPath = libPath.append('pkg/dartdoc');
 
   if (args.isEmpty()) {
     print('No arguments provided.');
     printUsage();
     return;
   }
 
   final entrypoints = <Path>[];
 
   var i = 0;
@@ skipping 126 matching lines @@
                              names.
 
  --exclude-lib=<libs>        Use this option to explicitly specify which
                              libraries to exclude from the documentation. If
                              omitted, no libraries are excluded. <libs> is
                              comma-separated list of library names.
 
  --verbose                   Print verbose information during generation.
 ''');
 }