Synchronize with PyXML 1.79: 73: Restore support for Python 2.1. 74: Factor the previous change differently 79: Conditionalize usage of PyTuple_Pack.
Synchronize with PyXML 1.79:
73: Restore support for Python 2.1.
74: Factor the previous change differently
79: Conditionalize usage of PyTuple_Pack.

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