Mainly this is following Linux to build own xml2/lzma/ssl/sqlite and linking
them all statically. This ensures the Python ssl module uses a recent openssl
version rather than a very old one shipped with macOS.
There is system-wide libz development package installed by default,
needed for some other dependencies. This patch ensures Python will
use our own self-compiled Zlib.
Note these are intended for platform maintainers, we do not intend to
support users making their own builds with these. For that precompiled
libraries from lib/ should be used.
Implemented by Martijn Berger, Ray Molenkamp and Brecht Van Lommel.
Differential Revision: https://developer.blender.org/D2753
