Merge branch 'patch-translation' into 'stable-3.1'

interface/web/admin/lib/lang/nl_software_package_list.lng

interface/web/mail/lib/lang/nl.lng

interface/web/mail/lib/lang/nl_mail_get.lng

interface/web/mail/lib/lang/nl_mail_user.lng

interface/web/mail/lib/lang/nl_mail_user_filter.lng

interface/web/mail/lib/lang/nl_mail_user_list.lng

interface/web/mail/lib/lang/nl_spamfilter_users.lng

interface/web/mailuser/lib/lang/nl.lng

...face/web/mailuser/lib/lang/nl_mail_user_autoresponder.lng

interface/web/mailuser/lib/lang/nl_mail_user_filter.lng