migrate void* object pointers to actual object type

[ArcRiley]

As the summary says, everywhere a parent/etc is typecast void* and is only NULL or an instance of one class, make it None or an instance of that class.

Instead of {{if ≠ == NULL :}}} use if <> is None :

Eliminate kludge code in property <> def __get__ :, just return that instance directly.

This is part of the migration to PyMill.