build_class(): one more (hopefully the last) step on the way to backwards compatibility.  When using the class of the first base as the metaclass, use its __class__ attribute in preference over its ob_type slot.  This ensures that we can still use classic classes as metaclasse, as shown in the original "Metaclasses" essay.  This also makes all the examples in Demo/metaclasses/ work again (maybe these should be turned into a test suite?).
build_class(): one more (hopefully the last) step on the way to
backwards compatibility.  When using the class of the first base as
the metaclass, use its __class__ attribute in preference over its
ob_type slot.  This ensures that we can still use classic classes as
metaclasse, as shown in the original "Metaclasses" essay.  This also
makes all the examples in Demo/metaclasses/ work again (maybe these
should be turned into a test suite?).

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator