Remove the PyType_Type assignments to _Type objects
Remove the PyType_Type assignments to _Type objects

Newer docs (since 3.5, which is what Travis tests) don't have this
anymore, only tp_new setting. tp_new is set directly in the type
objects, so it looks like this is not needed anymore. And it should
fix nightly testing, hopefully.

iustin/pylibacl,iustin/pylibacl