Build and handle jsfiles using webpack instead of django-pipeline.

Also renames bundle.js to translations.js.

static/js/translations.js

@@ -0,0 +1,56 @@
+// commonjs code goes here
+
+(function () {
+    var i18n = window.i18n = require('i18next');
+    var XHR = require('i18next-xhr-backend');
+    var lngDetector = require('i18next-browser-languagedetector');
+    var Cache = require('i18next-localstorage-cache');
+
+    var backendOptions = {
+        loadPath: '/static/locale/__lng__/translations.json',
+    };
+    var callbacks = [];
+    var initialized = false;
+
+    var detectionOptions = {
+        order: ['htmlTag'],
+        htmlTag: document.documentElement,
+    };
+
+    var cacheOptions = {
+        enabled: true,
+        prefix: 'i18next:' + page_params.server_generation + ':',
+        expirationTime: 2*7*24*60*60*1000,  // 2 weeks
+    };
+
+    i18n.use(XHR)
+        .use(lngDetector)
+        .use(Cache)
+        .init({
+            nsSeparator: false,
+            keySeparator: false,
+            interpolation: {
+                prefix: "__",
+                suffix: "__",
+            },
+            backend: backendOptions,
+            detection: detectionOptions,
+            cache: cacheOptions,
+            fallbackLng: 'en',
+        }, function () {
+            var i;
+            initialized = true;
+            for (i=0; i<callbacks.length; i += 1) {
+                callbacks[i]();
+            }
+        });
+
+    i18n.ensure_i18n = function (callback) {
+        if (initialized) {
+            callback();
+        } else {
+            callbacks.push(callback);
+        }
+    };
+
+}());