First running version (#2)

This currently depends of interacting with matrix_synapse_rest_auth[1] and mxisd[2].
How to integrate that is explained in the README

[1] https://github.com/kamax-io/matrix-synapse-rest-auth
[2] https://github.com/kamax-io/mxisd

language.php

@@ -0,0 +1,13 @@
+<?php
+$lang = "de-de";
+if(isset($_GET['lang'])){
+	$lang = filter_var($_GET['lang'], FILTER_SANITIZE_STRING);
+}
+$lang_file = dirname(__FILE__) . "/lang/lang.".$lang.".php";
+if (!file_exists($lang_file)) {
+	error_log("Translation for " . $lang . " not found. Fallback to 'de-de'");
+	$lang = "de-de";
+}
+require_once($lang_file);
+unset($lang_file);
+?>