Add dashboard warnings for system_username and notification_email site settings

app/models/admin_dashboard_data.rb

@@ -36,7 +36,9 @@ class AdminDashboardData
       contact_email_check,
       send_consumer_email_check,
       title_check,
-      access_password_removal ].compact
+      access_password_removal,
+      system_username_check,
+      notification_email_check ].compact
   end
 
   def self.fetch_all
@@ -137,6 +139,14 @@ class AdminDashboardData
     I18n.t('dashboard.consumer_email_warning') if Rails.env == 'production' and ActionMailer::Base.smtp_settings[:address] =~ /gmail\.com|live\.com|yahoo\.com/
   end
 
+  def system_username_check
+    I18n.t('dashboard.system_username_warning') if SiteSetting.system_username.blank?
+  end
+
+  def notification_email_check
+    I18n.t('dashboard.notification_email_warning') if SiteSetting.notification_email.blank?
+  end
+
 
   # TODO: generalize this method of putting i18n keys with expiry in redis
   #       that should be reported on the admin dashboard:

config/locales/server.en.yml

@@ -394,6 +394,8 @@ en:
     title_nag: "The title Site Setting is still set to the default value. Please update it with your site's title in the <a href='/admin/site_settings'>Site Settings</a>."
     consumer_email_warning: "Your site is configured to use Gmail (or another consumer email service) to send email. <a href='http://support.google.com/a/bin/answer.py?hl=en&answer=166852' target='_blank'>Gmail limits how many emails you can send</a>. Consider using an email service provider like mandrill.com to ensure email deliverability."
     access_password_removal: "Your site was using the access_password setting, which has been removed. The login_required and must_approve_users settings have been enabled, which should be used instead. You can change them in the <a href='/admin/site_settings'>Site Settings</a>. Be sure to <a href='/admin/users/list/pending'>approve users in the Pending Users list</a>. (This message will go away after 2 days.)"
+    system_username_warning: "The system_username setting is blank. Please update it in the <a href='/admin/site_settings'>Site Settings</a>. Set it to the username of an admin user who should be the sender of system messages."
+    notification_email_warning: "The notification_email setting is blank. Please update it in the <a href='/admin/site_settings'>Site Settings</a>."
 
   content_types:
     education_new_reply: