4.21.0 - build: Automate copyright year management - build: Define xfce4 min version >= 4.18 - Replace deprecated exo with libxfce4ui 4.21.0 - meson-build: Add tests option - meson-build: Use SPDX license expression - meson-build: Update debug/optimization flag management - autotools-build: Fix EXTRA_DIST redefinition - Add meson build - Set up GNU symbol visibility - garcon: Remove include guard from private header - garcon: Don't install garcon-marshal.h - Translation Updates: Albanian, Amharic, Arabic, Armenian, Armenian (Armenia), Asturian, Basque, Belarusian, Bengali, Bulgarian, Catalan, Chinese (China), Chinese (Hong Kong), Chinese (Taiwan), Croatian, Czech, Danish, Dutch, Eastern Armenian, English (Australia), English (United Kingdom), Esperanto, Estonian, Finnish, French, Galician, Georgian, German, Greek, Hebrew, Hindi, Hungarian, Icelandic, Indonesian, Interlingue, Italian, Japanese, Kabyle, Kazakh, Korean, Lithuanian, Malay, Norwegian Bokmål, Norwegian Nynorsk, Occitan (post 1500), Polish, Portuguese, Portuguese (Brazil), Romanian, Russian, Serbian, Slovak, Slovenian, Spanish, Swedish, Thai, Turkish, Ukrainian, Uyghur, Welsh