report PythonType as hashable - fixed cp35667
added test for cp35667
suppress MoveNext/CurrentValue during generator finalization

fixes cp35682
relaxed test cases depending on finalizer of generator
fixed typo in comment
Merge pull request #234 from paweljasinski/cp35667

report PythonType as hashable - fixed cp35667
Merge pull request #237 from paweljasinski/cp35682

suppress MoveNext/CurrentValue during generator finalization