i18n: Setup module and add translation-util.js

* Add i18n package.
* Use system locale for TranslationUtil.

app/renderer/js/utils/translation-util.js

@@ -0,0 +1,29 @@
+'use strict';
+const path = require("path");
+const electron = require("electron");
+const i18n = require("i18n");
+let instance = null;
+let app = null;
+/* To make the util runnable in both main and renderer process */
+if (process.type === 'renderer') {
+    app = electron.remote.app;
+}
+else {
+    app = electron.app;
+}
+class TranslationUtil {
+    constructor() {
+        if (instance) {
+            return this;
+        }
+        instance = this;
+        i18n.configure({
+            directory: path.join(__dirname, '../../../translations/'),
+            register: this
+        });
+    }
+    __(phrase) {
+        return i18n.__({ phrase, locale: app.getLocale() });
+    }
+}
+module.exports = new TranslationUtil();