gui: Upgrade Angular (v1.5.3 plus various), non-minified

gui/default/syncthing/app.js

@@ -51,6 +51,7 @@ syncthing.config(function ($httpProvider, $translateProvider, LocaleServiceProvi
 
     // language and localisation
 
+    $translateProvider.useSanitizeValueStrategy('escape');
     $translateProvider.useStaticFilesLoader({
         prefix: 'assets/lang/lang-',
         suffix: '.json'

gui/default/syncthing/core/syncthingController.js

@@ -1,6 +1,6 @@
 angular.module('syncthing.core')
     .config(function($locationProvider) {
-        $locationProvider.html5Mode(true).hashPrefix('!');
+        $locationProvider.html5Mode({enabled: true, requireBase: false}).hashPrefix('!');
     })
     .controller('SyncthingController', function ($scope, $http, $location, LocaleService, Events, $filter) {
         'use strict';