Ddupdate

* Remove the straight.plugins dependency.
* config: Fix bug creating new config files like ~/.config/dduodate.conf
* config: Add new address plugin option "Use address as of service".
* build: Don't install documentation files (bad idea from beginning).
* Miscellanaous cleanup and doc fixes.

* Drop the dnsdynamic plugin, service is discontinued.
* Drop the system-ns plugin, service is discontinued.
* Add new plugin for desec.io (36).
* Handle expired certificate on duiadns server.
* myonlineportal, dnsexit, dynu: Handle API updates.
* Multiple bugfixes in new credentials backends.
* Base64-encode passwords in auth_netrc to handle 'strange' characters (49).
* Add support for selecting auth plugin to ddupdate-config.
* ddplugin: Add a new header kwarg argument to get_response(), used in
desec.io to allow token based header authentication.
* Add pyproject.toml, first step in distutils being dropped in 3.12
* Various documentation polish.
* Rename all address plugins using an addr_ prefix.
* Fix pylint and pycodestyle diagnostics.

* Support multiple configuration sections in config file (25)
* Experimental support for keyring password storage (23)
* Add FINAL_PREFIX environment variable support to ease packaging
* Support multiple credentials for Google domains (52)
* New address plugin for OnHub/Google WiFi/Nest WiFi (58)
* New dnshome.de address- and service plugins (47)
* Plugins: freedns: Update to simplified https API.
Thanks to m-jung, Alexey Grevtsev, Marcin Mielniczuk, Gabriel de Perthuis

* Fix wrong path in systemd service file (54).
* Fix bad return value causing systemd problems (53).
* Graceful exist on missing python-requests (48).
Thanks to Teemo Ikonen

* Fix ip route parsing (35)
* Fix python 3.9 syntax warnings (38, 37)
* New plugin domains.google.com -- googledomains.py
* Error logging bugfixes (4411454).
Thanks to aerusso, LoganK and Hroncok

* Fix address-options and service-options parsing regression (24).
* Add new nsupdate(1) plugin (29).
* Install systemd files in correct user locations (22).
* Enhance ipv6 address parsing in address plugins (28).
* Patch ddupdate.service script path on installation.
* Thanks to aerusso for nsupdate plugin, bugfixes and enhancements.