Build failure on Windows with Python 3.10

[pkgw]

It looks like this package won't build on Windows with Python 3.10 due to the lack of definition of a ssize_t symbol — see conda-forge/openexr-python-feedstock#4 . My guess is that in 3.10 Python.h stops including some system header that was needed.

Based on my read of the code, I think it should fix things to replace the two instances of ssize_t with Py_ssize_t in OpenEXR.cpp.

[jamesbowman]

This code is no longer maintained -- see https://github.com/sanguinariojoe/pip-openexr