Show scan rate in web GUI

gui/index.html

@@ -228,7 +228,7 @@
                   <span ng-switch-when="scanning">
                     <span class="hidden-xs" translate>Scanning</span>
                     <span class="hidden-xs" ng-if="scanPercentage(folder.id) != undefined">
-                        ({{scanPercentage(folder.id)}}%)
+                      (<span class="hidden-xs" ng-if="scanRate(folder.id) > 0">{{scanRate(folder.id) | binary}}B/s, </span>{{scanPercentage(folder.id)}}%)
                     </span>
                     <span class="visible-xs">&#9724;</span>
                   </span>

gui/syncthing/core/syncthingController.js

@@ -321,7 +321,8 @@ angular.module('syncthing.core')
             var data = arg.data;
             $scope.scanProgress[data.folder] = {
                 current: data.current,
-                total: data.total
+                total: data.total,
+                rate: data.rate,
             };
             console.log("FolderScanProgress", data);
         });
@@ -668,6 +669,13 @@ angular.module('syncthing.core')
             return Math.floor(pct);
         }
 
+        $scope.scanRate = function (folder) {
+            if (!$scope.scanProgress[folder]) {
+                return 0;
+            }
+            return $scope.scanProgress[folder].rate;
+        }
+
         $scope.deviceStatus = function (deviceCfg) {
             if ($scope.deviceFolders(deviceCfg).length === 0) {
                 return 'unused';