databases/mysql_config_editor: new port

Stock MySQL distribution includes mysql_config_editor utility
that can convert my.cnf-like text file with passwords
to binary obfuscated format storing AES-encrypted original data
with corresponding encryption key, so other utilities
could decrypt it to use passwords non-interactively.

However, this dialog-based utility does not perform batch mode
conversion nor will it de-obfuscate passwords.

This python script can generate same binary files non-interactively
and it can show passwords from such files.