check for redefining of methods and forbid

causing some test problems, but better that way (until it's done right off course)

test/parfait/test_vool_method.rb

@@ -22,7 +22,7 @@ module Vool
     end
     def test_method
       clazz =  @clazz.to_parfait
-      assert_equal Parfait::VoolMethod , method.to_parfait(clazz).class
+      assert_equal Parfait::VoolMethod , clazz.get_instance_method(:main).class
     end
   end
 end