(css) Visually identify attendees with no freebusy

UI/Templates/SchedulerUI/UIxAttendeesEditor.wox

@@ -41,7 +41,9 @@
         </div>
       </md-list-item>
       <md-list-item ng-repeat="currentAttendee in editor.component.attendees track by currentAttendee.email">
-        <div class="hour" ng-repeat="hour in ::editor.attendeesEditor.hours">
+        <div class="hour"
+             ng-class="{'sg-no-freebusy': !currentAttendee.uid}"
+             ng-repeat="hour in ::editor.attendeesEditor.hours">
           <div class="quarter" ng-class="{event: editor.component.coversFreeBusy(day.getDayString, hour, 0)}">
             <div class="busy" ng-show="currentAttendee.freebusy[day.getDayString][hour][0]"><!-- 15 minutes --></div>
           </div>

UI/WebServerResources/scss/views/SchedulerUI.scss

@@ -556,6 +556,15 @@ $block_radius: 3px;
     flex-grow: 0;
     flex-basis: 17px; // hour's width + hour's border
     align-items: stretch;
+    &.sg-no-freebusy {
+      background-color: sg-color($sogoPaper, 200);
+      background-image: repeating-linear-gradient(-45deg,
+                                                  rgb(255,255,255),
+                                                  rgb(255,255,255) 2px,
+                                                  transparent 2px,
+                                                  transparent 4px);
+      opacity: 0.5;
+    }
   }
   .quarter {
     min-width: 4px;