add lang: nl + deprecate lang/_target

resources/lang/en/message.php

@@ -51,4 +51,18 @@ BODY,
         'subject' => 'Exam :exam_name end time changed',
         'body' => 'The end time of your in-progress exam :exam_name has changed from :old_end_time to :new_end_time. admin: :operator, reason: :reason.',
     ],
+
+    'mail_dear' => "Dear ",
+    'mail_you_received_a_pm' => "You have received a PM.",
+    'mail_sender' => "Sender	",
+    'mail_subject' => "Subject	",
+    'mail_date' => "Date		",
+    'mail_use_following_url' => "You can click ",
+    'mail_use_following_url_1' => " to view the message (you may have to login).",
+    'mail_yours' => "<br />Yours,",
+    'mail_the_site_team' => "The %s Team.",
+    'mail_received_pm_from' => "You have received a PM from ",
+    'mail_here' => "HERE",
+    'msg_system' => "System",
+    'msg_original_message_from' => "Original Message from ",
 ];