Upgrade packaging to 16.8

Add python_requires to setup.py

Make Entrypoint methods docs up to date.

Fix #849 global-exclude globbing

package_index: fix bug not catching some network timeouts

Use super to resolve the superclass, but fall back to direct access on Python 2 where old style classes are used. Ref #843.

Remove _add_defaults_data_files override and add unittest

Merge branch 'suppress-warning' of https://github.com/abstrus/setuptools into abstrus-suppress-warning

Entrypoint.load() is deprecated and it's recommend to use `require` and
`resolve` separately.

After #764, `global-exclude .pyc` no longer excluded `.pyc` files.
This fixes that regression, and adds a test for this behaviour.

Drop exception support for packages triggering win32com cache generation during build/install. Fixes #841

There are already so many exceptions catched, like socket errors (e.g. failure
in name resolution) or HTTP errors. Depending on when a timeout occurs, it is
either catched (URLError during the SSL handshake) or not (socket.error while
getting a HTTP response).

When used by buildout, this fixes random failures when running in newest mode
(which is the default case), or when the requested version is available in the
download-cache.