Two small docgen fixes

pkg/docgen/lib/docgen.dart

 // Copyright (c) 2013, 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.
 
 /// **docgen** is a tool for creating machine readable representations of Dart
 /// code metadata, including: classes, members, comments and annotations.
 ///
 /// docgen is run on a `.dart` file or a directory containing `.dart` files.
 ///
 ///      $ dart docgen.dart [OPTIONS] [FILE/DIR]
@@ skipping 181 matching lines @@
 }
 
 String _packageIntro(packageDir) {
   var dir = new Directory(packageDir);
   var files = dir.listSync();
   var readmes = files.where((FileSystemEntity each) => (each is File &&
       each.path.substring(packageDir.length + 1, each.path.length)
           .startsWith('README'))).toList();
   if (readmes.isEmpty) return '';
   // If there are multiples, pick the shortest name.
-  readmes.sort((a, b) => a.length.compareTo(b.length));
+  readmes.sort((a, b) => a.path.length.compareTo(b.path.length));
   var readme = readmes.first;
   var linkResolver = (name) => fixReference(name, null, null, null);
   var contents = markdown.markdownToHtml(readme
     .readAsStringSync(), linkResolver: linkResolver,
     inlineSyntaxes: markdownSyntaxes);
   return contents;
 }
 
 List<Uri> _listLibraries(List<String> args) {
   var libraries = new List<Uri>();
@@ skipping 936 matching lines @@
         // with the mixin as an owner private too.
         entityMap.values.where((e) => e.owner == qualifiedName).forEach(
             (element) => element.isPrivate = true);
         // Move the subclass up to the next public superclass
         subclasses.forEach((subclass) => addSubclass(subclass));
       } else {
         // It is an exported item. Loop through each of the exported types,
         // and tell them to update their links, given these other exported
         // names within the library.
         for (Exported member in library._exportedMembers.values) {
-          member.updateExports(library._exportedMembers.keys);
+          member.updateExports(library._exportedMembers);
         }
       }
     }
   }
 
   /// Makes sure that all methods with inherited equivalents have comments.
   void ensureComments() {
     if (_commentsEnsured) return;
     _commentsEnsured = true;
     inheritedMethods.forEach((qualifiedName, inheritedMethod) {
@@ skipping 531 matching lines @@
 /// Remove statics from the map of inherited items before adding them.
 Map _filterStatics(Map items) {
   var result = {};
   items.forEach((name, item) {
     if (!item.isStatic) {
       result[name] = item;
     }
   });
   return result;
 }