[VS2015] Compile error C2782: 'ssize_t' in PyImathFixedMatrix

[JenusL]

I'm building OpenEXR with Python 3.6 bindings on Windows with Boost 1.66 and MSVC 14 (VS2015).
I got the following compile error:
openexr\pyilmbase\pyimath\PyImathFixedMatrix.h(144): error C2872: 'ssize_t': ambiguous symbol

As far as I can tell that is the only use of ssize_t in the whole project. I changed it to Py_ssize_t to get it to compile but I don't know if that is the proper solution.

[meshula]

Good catch. Not only should Py_ssize_t be used, but convert_index should be fixed to take and return a Py_ssize_t instead of an it.

[cary-ilm]

Fixed in #415