Merge branch 'master' into files_encryption

CONTRIBUTING.md

apps/files/l10n/ca.php

apps/files/l10n/de_DE.php

apps/files/l10n/es.php

apps/files/l10n/et_EE.php

apps/files/l10n/fr.php

apps/files/l10n/gl.php

apps/files/l10n/it.php

apps/files/l10n/ja_JP.php

apps/files/l10n/nl.php

apps/files/l10n/nn_NO.php

apps/files/l10n/pl.php

apps/files/l10n/pt_BR.php

apps/files/l10n/ru_RU.php

apps/files/l10n/zh_CN.php

apps/files_trashbin/l10n/ru_RU.php

apps/user_ldap/ajax/clearMappings.php

apps/user_ldap/css/settings.css

apps/user_ldap/js/settings.js

apps/user_ldap/l10n/ar.php