Fix notification background

src/stylesheets/css/Lungo.widgets.notification.css

@@ -11,6 +11,7 @@
   width: 100%;
   height: 100%;
   z-index: 3;
+  display: none;
   background-color: rgba(0,0,0,0.75);
 }
 .notification .window {

src/stylesheets/lungo.widgets.notification.styl

@@ -18,8 +18,7 @@ LOADING = 104px
   width: 100%
   height: 100%
   z-index: 3
-  // display: none
-
+  display: none
   background-color: OPACITY
 
   & .window