Python3

Work in progress.

Thinks, that have automated tests works.

The template is broken, don't know why.

**UPDATE:** the template works, there was a problem in my browser-cache
The attribute `verbose_name` could only be a string. There is no `__str__` method that has to be called. So `str(` can be removed.
(Before there was `unicode()` because the method should return an unicode object instead of a bytestring.