Fixed inheritance not going from Object to all other classes

pkg/docgen/lib/docgen.dart

Index: pkg/docgen/lib/docgen.dart
diff --git a/pkg/docgen/lib/docgen.dart b/pkg/docgen/lib/docgen.dart
index 6f65e8a8b2db98d5b992fc8f1050fd1dd3ce5393..5fe681a96de2a5f91a6f94a7cd41edd144851ba1 100644
--- a/pkg/docgen/lib/docgen.dart
+++ b/pkg/docgen/lib/docgen.dart
@@ -404,6 +404,11 @@ Class _class(ClassMirror mirror) {
         interfaces.toList(), _variables(mirror.variables),
         _methods(mirror.methods), _annotations(mirror), _generics(mirror), 
         mirror.qualifiedName, _isHidden(mirror), mirror.owner.qualifiedName);
+    if (superclass != null)
+      clazz.addInherited(superclass);
+    interfaces.forEach((interface) {
+      clazz.addInherited(interface);
+    });
     entityMap[mirror.qualifiedName] = clazz;
   }
   return clazz;
@@ -700,7 +705,6 @@ class ClassGroup {
       if (_isVisible(clazz)) {
         parent.addSubclass(clazz);
       }
-      clazz.addInherited(parent);
     });
 
     clazz.ensureComments();