piwigo16-languages

fix(i18n): rebuild zip archives after day/month PO patch

fix(i18n): add piwigo_day_N/piwigo_month_N entries to 56 common.po files; rebuild zip archives

feat(i18n): rebuild all 62 zip files with PO format (no .lang.php)

feat(i18n): migrate 314 .lang.php files to gettext PO format

i18n: translate embedded non-English text in 6 descriptions