Update dutch translation.

program/localization/nl_NL/labels.inc

@@ -115,6 +115,8 @@ $labels['viewsource'] = 'Toon bron';
 $labels['markmessages'] = 'Markeer berichten';
 $labels['markread'] = 'Gelezen';
 $labels['markunread'] = 'Ongelezen';
+$labels['markflagged'] = 'Selecteren';
+$labels['markunflagged'] = 'Niet selecteren';
 $labels['select'] = 'Selecteer';
 $labels['all'] = 'Allemaal';
 $labels['none'] = 'Geen';
@@ -197,6 +199,7 @@ $labels['dstactive'] = 'Zomertijd';
 $labels['htmleditor'] = 'Maak HTML berichten aan';
 $labels['htmlsignature'] = 'HTML onderschrift';
 $labels['previewpane'] = 'Toon voorbeeldvenster';
+$labels['skin'] = 'Opmaakprofiel';
 $labels['logoutclear'] = 'Prullenbak legen bij uitloggen';
 $labels['logoutcompact'] = 'Postvak IN opschonen bij uitloggen';
 $labels['uisettings'] = 'Gebruikers Interface';