added ajaxify popstate cache, so back/forward will just put back the already loaded page

public/src/ajaxify.js

@@ -1,9 +1,11 @@
 "use strict";
 
-var ajaxify = ajaxify || {};
+var ajaxify = ajaxify || {
+	isPopState: false
+};
 
 $(document).ready(function() {
-	require(['templates'], function (templatesModule) {
+	require(['templates', 'ajaxifyCache'], function (templatesModule, cache) {
 		/*global app, templates, utils, socket, translator, config, RELATIVE_PATH*/
 
 		var location = document.location || window.location,
@@ -13,7 +15,9 @@ $(document).ready(function() {
 
 		window.onpopstate = function (event) {
 			if (event !== null && event.state && event.state.url !== undefined && !ajaxify.initialLoad) {
+				ajaxify.isPopState = true;
 				ajaxify.go(event.state.url, function() {
+					ajaxify.isPopState = false;
 					$(window).trigger('action:popstate', {url: event.state.url});
 				}, true);
 			}
@@ -55,6 +59,12 @@ $(document).ready(function() {
 			// "quiet": If set to true, will not call pushState
 			app.enterRoom('');
 
+			// If the url is in the cache, load from cache instead
+			if (cache.get(url)) { return true; }
+			else {
+				cache.url = ajaxify.currentPage;
+			}
+
 			$(window).off('scroll');
 
 			if ($('#content').hasClass('ajaxifying') && apiXHR) {
@@ -114,6 +124,7 @@ $(document).ready(function() {
 			templates.parse(tpl_url, data, function(template) {
 				translator.translate(template, function(translatedTemplate) {
 					setTimeout(function() {
+						cache.set();
 						$('#content').html(translatedTemplate);
 
 						ajaxify.variables.parse();