*#1424:Preventkeepingfilesmodeforpackage_databuild.Itmaybreakabuildifuser's package data has read only flag.
* #1431: In ``easy_install.check_site_dir``, ensure the installation directory exists.
* #1563: In ``pkg_resources`` prefer ``find_spec`` (PEP 451) to ``find_module``.
Incorporate changes from v44.1.0:
* #1704: Set sys.argv[0] in setup script run by build_meta.__legacy__
* #1959: Fix for Python 4: replace unsafe six.PY3 with six.PY2
* #1994: Fixed a bug in the "setuptools.finalize_distribution_options" hook that lead to ignoring the order attribute of entry points managed by this hook.