Add method to Note to create notes about status changes.

app/models/note.rb

@@ -42,6 +42,14 @@ class Note < ActiveRecord::Base
 
   mount_uploader :attachment, AttachmentUploader
 
+  def self.create_status_change_note(noteable, author, status)
+    create({ :noteable => noteable,
+             :project => noteable.project,
+             :author => author,
+             :note => "_Status changed to #{status}_" },
+          :without_protection => true)
+  end
+
   def notify
     @notify ||= false
   end