Update nl_NL translation.

program/localization/nl_NL/labels.inc

@@ -232,6 +232,11 @@ $labels['everynminutes'] = 'iedere $n minuten';
 $labels['never'] = 'nooit';
 $labels['messagesdisplaying'] = 'Berichten weergave';
 $labels['messagescomposition'] = 'Berichten aanmaken';
+$labels['mimeparamfolding'] = 'Namen van bijlagen';
+$labels['2231folding'] = 'Volledig RFC 2231 (Thunderbird)';
+$labels['miscfolding'] = 'RFC 2047/2231 (MS Outlook)';
+$labels['2047folding'] = 'Volledig RFC 2047 (andere)';
+$labels['advancedoptions'] = 'geavanceerde opties';
 $labels['folder'] = 'Map';
 $labels['folders'] = 'Mappen';
 $labels['foldername'] = 'Mapnaam';