Add initial REST API structure with starter files

Library/Msg.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace ppb\Library;
+
+class Msg
+{
+    /**
+     * Sends either an error or a success message as JSON Object. The error message contains 
+     * additional informations about the error. If no individual msg is given as parameter, 
+     * the default msg will be send
+     *
+     * @param boolean $isError is the msg an error msg?
+     * @param string $msg optional error message
+     * @param string $ex optional debug message
+     */
+    public function __construct($isError = false, $msg = '', $ex = '')
+    {
+        if ($isError) {
+            $striped = strip_tags($ex);
+            echo json_encode(array(
+                "isError" => true,
+                "msg" => is_null($msg) ? 'Ihre Anfrage konnte nicht verarbeitet werden' : $msg,
+                "ex" => $striped
+            ));
+        } else {
+            echo json_encode(array("isError" => false));
+        } 
+        die;
+    }
+}