[l10n] Updated Italian translation.
Updated Hungarian translation
Updated Polish translation
Fix CSD window decorations

https://bugzilla.gnome.org/show_bug.cgi?id=708407
NEWS update
bump version to 3.9.92
Updated Korean translation
Update Arabic translation
Updated Lithuanian translation
Updated Slovenian translation
Updated Galician translations
Updated German translation
Install a valid XML AppData file
Updated Czech translation
NEWS updates, bump version to 3.10.0