Fix empty namespace package wheel install

Remove "upload" and "register" commands.

The upload and register commands were deprecated over a year ago, in
July 2018 (PR GH-1410, discussed in issue GH-1381). It is time to
actively remove them in favor of twine.

Upgrade setuptools.depends to importlib from depracated imp

Fix code for detecting Visual Studio's version on Windows under Python 2.

pkg_resources: fix ``Requirement`` hash/equality implementation

Document using asterisk in package_data section

docs: drop ez_setup documentation and related references

doc: drop most references to EasyInstall

Add Python 3.8 final to Travis test matrix

Fixes for python3.10

Improve Visual C++ 14.X support

Document support for Python 3.8 through a trove classifier

Remove outdated comment and suppressed exception from test_test.py

The test command has not called sys.exit since commit
2c4fd432.