Make links to libraries from the main page work

pkg/docgen/lib/src/generator.dart

 // Copyright (c) 2014, 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 docgen.generator;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:io';
@@ skipping 405 matching lines @@
 void generateLibrary(dart2js_mirrors.Dart2JsLibraryMirror library) {
   var result = new Library(library);
   result.updateLibraryPackage(library);
   logger.fine('Generated library for ${result.name}');
 }
 
 /// If we can't find the SDK introduction text, which will happen if running
 /// from a snapshot and using --parse-sdk or --include-sdk, then use this
 /// hard-coded version. This should be updated to be consistent with the text
 /// in docgen/doc/sdk-introduction.md
+// TODO(alanknight): It would be better if we could resolve the references to
+// dart:core etc. at load-time in the viewer. dartbug.com/20112
 const _DEFAULT_SDK_INTRODUCTION =
     """
 Welcome to the Dart API reference documentation,
 covering the official Dart API libraries.
 Some of the most fundamental Dart libraries include:
 
-* [dart:core](#dart:core):
+* [dart:core](./dart:core):
   Core functionality such as strings, numbers, collections, errors,
   dates, and URIs.
-* [dart:html](#dart:html):
+* [dart:html](./dart:html):
   DOM manipulation for web apps.
-* [dart:io](#dart:io):
+* [dart:io](./dart:io):
   I/O for command-line apps.
 
 Except for dart:core, you must import a library before you can use it.
 Here's an example of importing dart:html, dart:math, and a
 third popular library called
 [polymer.dart](http://www.dartlang.org/polymer-dart/):
 
     import 'dart:html';
     import 'dart:math';
     import 'package:polymer/polymer.dart';
@@ skipping 15 matching lines @@
   * [Samples](http://www.dartlang.org/samples/)
   * [A Tour of the Dart Libraries](http://www.dartlang.org/docs/dart-up-and-running/contents/ch03.html)
 
 This API reference is automatically generated from the source code in the
 [Dart project](https://code.google.com/p/dart/).
 If you'd like to contribute to this documentation, see
 [Contributing](https://code.google.com/p/dart/wiki/Contributing)
 and
 [Writing API Documentation](https://code.google.com/p/dart/wiki/WritingApiDocumentation).
 """;