- BC Break: _PHP_ namespaces changed (PSR-4 standard). The _root_ namespace for all _PF_ related scripts is Exodus4D\Pathfinder

- BC Break: Project folder structure changed. Removed `app/main` dir.
- BC Break: Core _PHP_ framework + dependencies moved into `composer.json` and are no longer part of this repo

app/Exception/DateException.php

@@ -0,0 +1,20 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: Exodus 4D
+ * Date: 29.11.2018
+ * Time: 18:12
+ */
+
+namespace Exodus4D\Pathfinder\Exception;
+
+
+class DateException extends PathfinderException {
+
+    /**
+     * @var array
+     */
+    protected $codes = [
+        3000 => 500         // invalid DateRange
+    ];
+}