Add newsletter star rating on hover

data/interfaces/default/newsletter_config.html

@@ -439,6 +439,7 @@
     });
 
     function previewNewsletter() {
+        showMsg('<i class="fa fa-check"></i>&nbsp; Check pop-up blocker if no response.', false, true, 2000);
         window.open('preview_newsletter?newsletter_id=' + $('#newsletter_id').val());
     }