The main task file now:
 - creates the bin directory (default /opt/warden-filer)
 - copies the binaries properly
 - applies executable permission to the init.d script
 - creates main binary symlink at /usr/local/bin/warden_filer.py
 - creates /etc/default/warden_filer_receiver file in the correct path

to prevent clashing of underscores in client names and underscores used by LIKE.

In MYSQL 8.0 one cannot create users using GRANT.
https://dev.mysql.com/doc/refman/8.0/en/mysql-nutshell.html#mysql-nutshell-removals
(MariaDB worked fine)

This did not work for python 3.9 and 3.10 (each for a different reason)
The context management of the cursor, seems to have been an undocumented feature
for at least six years.

Simplify data download and unnecessary config, add CESNET banners and legend, more interesting arcs animation

Revert shebang python executable name from python3 back to python. World is not yet ready for this change.