fix test failure in unittest_regrtest, due to change in the handling of extensions loading
fix test failure in unittest_regrtest, due to change in the handling of extensions loading

Allowing to load arbitrary extensions fix test_new_style_class_detection but
make test_numpy_crash fail because inference seems to do a better job than
before and doesn't return anymore a YES object. As this test only checks that it
doesn't crash, simply stop checking this.

Closes #62

PyCQA/astroid