merge master into filesystem

apps/files/ajax/delete.php

apps/files/css/files.css

apps/files/js/filelist.js

apps/files/js/files.js

apps/files/l10n/de.php

apps/files/l10n/de_DE.php

apps/files/l10n/eu.php

apps/files/l10n/ru.php

apps/files_external/l10n/ar.php

apps/files_external/l10n/bg_BG.php

apps/files_external/l10n/ca.php

apps/files_external/l10n/cs_CZ.php

apps/files_external/l10n/es.php

apps/files_external/l10n/es_AR.php

apps/files_external/l10n/fa.php

apps/files_external/l10n/hr.php

apps/files_external/l10n/hu_HU.php

apps/files_external/l10n/ia.php

apps/files_external/l10n/it.php

apps/files_external/l10n/ja_JP.php