Fix meta_class, sis class instance variables and class methods

after some serious recursive thinking it now actually makes sense.
The key was to change the actual type of the class that the meta_class manages
For objects it's (still) ok just to change the instance_type, but since the class object exists and has type, when adding instance variables, that actual type has to change

test/vool/class_send/test_class_send_inherited.rb

@@ -40,7 +40,7 @@ module Vool
       assert_equal SimpleCall,  @ins.next(2).class
       assert_equal :one_plus,  @ins.next(2).method.name
       assert_equal Parfait::Type,  @ins.next(2).method.self_type.class
-      assert_equal :Object,  @ins.next(2).method.self_type.object_class.name
+      assert_equal :Class,  @ins.next(2).method.self_type.object_class.name
     end
   end
 end