Finish documenting internal stuff. See Changelog for other details

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@5364 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/rdoc/ri/ri_descriptions.rb

@@ -100,6 +100,12 @@ module RI
       "Module"
     end
 
+    # the 'ClassDescription' subclass overrides this
+    # to format up the name of a parent
+    def superclass_string
+      nil
+    end
+
     private
 
     def merge(into, from)
@@ -116,6 +122,14 @@ module RI
     def display_name
       "Class"
     end
+
+    def superclass_string
+      if @superclass && @superclass != "Object"
+        @superclass
+      else
+        nil
+      end
+    end
   end