ANN: Beta version of Webware for Python 3

Hi all,

the final ever Python 2 update has been released in April, which also 
marks the end of the era of Webware for Python 2.

But don't despair - Webware for Python 3 has been available as an alpha 
release since last year, and as a beta release since today.

The home page for Webware for Python 3 has been moved here:
https://github.com/WebwareForPython/w4py3/

Documentation is available here:
https://webwareforpython.github.io/w4py3/

The documentation also lists the changes and explains how to migrate 
legacy Webware applications.

Main improvements and changes:
- Use Python 3.6 or newer instead of Python 2
- Use standard packaging and installation
- Use entry points for Webware plug-ins
- Use WSGI instead of app server and adapters
- Use Sphinx/ReadTheDocs for documentation
- Use GitHub Actions to run improved test suite

The WebKit plug-in has been promoted to the top level and does not exist 
any more as a separate plug-in. PSP is still built-in.

MiddleKit has been removed as a built-in plug-in, but can be installed 
as an external plug-in available from here:
https://github.com/WebwareForPython/w4py3-middlekit

Please let me know how you like the beta version, if there are any pain 
points, bugs or other problems, since I want to release a final version 
soon. New features and more modernizations will be released in the next 
minor version. You can use GitHub issues, pull requests or the 
[email protected] mailing list for feedback and 
sending bug reports or improvements.

Stay healthy and happy!

-- Christoph