Log Message:
xfce4-session: update to 4.18.0

Change log:

4.18.0 (2022-12-15)
======
- build: Bump requirements for Xfce 4.18
- Translation Updates:
  Russian, Turkish

4.17.2 (2022-12-01)
======
- logout-dialog: New Xfconf property "ShowSave" (!29)
- bump copyright year to 2022

4.17.1 (2022-11-01)
======

- Translation Updates:
  Portuguese

4.17.0 (2022-09-14)
======
- settings: Revert type hint change
- Check getgrgid(3) return value to avoid crash
- build: Fix intltool lock file problem during make distcheck
- Remove pre-defined lockers
- Refresh list of screensavers (#17)
- Do not mind output of screensaver, if successful
- Run custom command in a separate shell
- Avoid extra pause by redirecting stdin
- Update COPYING
- Increase switch user timeout (!25)
- xflock4: Apply initial delay before running a screensaver/locker (#29)
- xflock4: Update copyrights
- xflock4: make the script executable
- Add labels to inline toolbar buttons
- Use correct icon for Close button
- Translation Updates:
  Albanian, Arabic, Armenian (Armenia), Asturian, Azerbaijani, Basque,
  Belarusian, Belarusian (Tarask), Bengali, Bulgarian, Catalan, Chinese
  (China), Chinese (Hong Kong), Chinese (Taiwan), Croatian, Czech,
  Danish, Dutch, Eastern Armenian, English (Australia), English
  (Canada), English (United Kingdom), Estonian, Finnish, French,
  Galician, German, Greek, Hebrew, Hindi, Hungarian, Icelandic,
  Indonesian, Interlingue, Italian, Japanese, Kazakh, Korean,
  Lithuanian, Malay, Norwegian Bokm��l, Norwegian Nynorsk, Occitan
  (post 1500), Persian (Iran), Polish, Portuguese, Portuguese (Brazil),
  Romanian, Russian, Serbian, Slovak, Slovenian, Spanish, Swedish,
  Thai, Turkish, Ukrainian, Uyghur, Vietnamese