fixes #635 - FFmpeg not being stopped in safari

MediaBrowser.WebDashboard/ApiClient.js

@@ -1402,6 +1402,19 @@ MediaBrowser.ApiClient = function ($, navigator, JSON, WebSocket, setTimeout, wi
             });
         };
 
+        self.stopActiveEncodings = function () {
+
+            var url = self.getUrl("Videos/ActiveEncodings", {
+
+                deviceId: deviceId
+            });
+
+            return self.ajax({
+                type: "DELETE",
+                url: url
+            });
+        };
+
         self.updateItemImageIndex = function (itemId, itemType, itemName, imageType, imageIndex, newIndex) {
 
             if (!imageType) {