Merge remote-tracking branch 'upstream/master' into master-sync-upstream

apps/comments/l10n/en_GB.js

apps/comments/l10n/en_GB.json

apps/comments/l10n/fr.js

apps/comments/l10n/fr.json

apps/comments/l10n/nl.js

apps/comments/l10n/nl.json

apps/comments/l10n/pt_BR.js

apps/comments/l10n/pt_BR.json

apps/comments/l10n/pt_PT.js

apps/comments/l10n/pt_PT.json

apps/comments/l10n/ru.js

apps/comments/l10n/ru.json

apps/comments/l10n/sl.js

apps/comments/l10n/sl.json

apps/dav/lib/CardDAV/ImageExportPlugin.php

apps/dav/tests/unit/CardDAV/ImageExportPluginTest.php

apps/federatedfilesharing/l10n/fr.js

apps/federatedfilesharing/l10n/fr.json

apps/federation/l10n/lb.js

apps/federation/l10n/lb.json