Add bg images to cache list

www/cache.js

@@ -1,4 +1,4 @@
-/* 
+/*
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
@@ -35,6 +35,18 @@ var cachedurls = [
     'assets/images/signatures.png',
     'assets/images/smallpackage.png',
     'assets/images/smallpackages.png',
+    'assets/images/bgs/add.svg',
+    'assets/images/bgs/list.svg',
+    'assets/images/bgs/map.svg',
+    'assets/images/bgs/notes.svg',
+    'assets/images/bgs/settings.svg',
+    'assets/images/bgs/toolbox.svg',
+    'assets/images/bgs/toolbox_addrlookup.svg',
+    'assets/images/bgs/toolbox_log.svg',
+    'assets/images/bgs/toolbox_scanner.svg',
+    'assets/images/bgs/toolbox_sharelist.svg',
+    'assets/images/bgs/toolbox_track.svg',
+    'assets/images/bgs/toolbox_weather.svg',
 
     'assets/css/app.css',
     'assets/css/backdrop.css',