Include an [OpenStreetMap] prefix on the subject of message notifications

Put back the [OpenStreetMap] prefix to the subject line of email
notifications of messages, but strip it again from any incoming
email replies.

app/models/notifier.rb

@@ -48,7 +48,7 @@ class Notifier < ActionMailer::Base
   def message_notification(message)
     common_headers message.recipient
     from_header message.sender.display_name, "m", message.id, message.digest
-    subject message.title
+    subject I18n.t('notifier.message_notification.subject_header', :user => message.title, :locale => locale)
     body :to_user => message.recipient.display_name,
          :from_user => message.sender.display_name,
          :body => message.body,

config/locales/en.yml

@@ -1062,6 +1062,7 @@ en:
       header: "{{from_user}} has commented on your recent OpenStreetMap diary entry with the subject {{subject}}:"
       footer: "You can also read the comment at {{readurl}} and you can comment at {{commenturl}} or reply at {{replyurl}}"
     message_notification:
+      subject_header: "[OpenStreetMap] {{subject}}"
       hi: "Hi {{to_user}},"
       header: "{{from_user}} has sent you a message through OpenStreetMap with the subject {{subject}}:"
       footer1: "You can also read the message at {{readurl}}"

script/deliver-message

@@ -15,6 +15,7 @@ else
   digest = message.digest
   from = message.recipient
   to = message.sender
+  subject = message.subject.sub(/\[OpenStreetMap\] */, "")
 end
 
 exit 0 unless recipient[3] == digest[0,6]
@@ -23,7 +24,7 @@ mail = TMail::Mail.parse(STDIN.readlines.join)
 
 message = Message.new(:sender => from, :recipient => to,
                       :sent_on => Time.now.getutc,
-                      :title => mail.subject,
+                      :title => subject,
                       :body => mail.body)
 message.save!