CodeIgniter 3.1.11 -> 3.4.5 (pocketarc fork) en PHP 8.3-fixes

- system/ vervangen door CodeIgniter 3.4.5 (pocketarc/codeigniter, PHP 8.2-8.5 compatibel)
- config.php, mimes.php, user_agents.php en error-views bijgewerkt naar 3.4.5
- composer.json: php-constraint "^7.4 || ^8.0" zodat composer install op 8.3 werkt
- PHP 8-fatals opgelost: count()/array-functies op FALSE/null, rekenen met lege
  strings, delen door nul, property zetten op FALSE, curly-brace string offsets,
  ongedefinieerde constanten, foute curl_setopt in Phantom_model::create_img
- dynamic properties gedeclareerd in libraries, optionele parameters voor verplichte opgelost
- vergelijkingen waar '' == 0 in PHP 8 anders uitvalt gecast naar (int)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

system/core/Router.php

@@ -6,7 +6,7 @@
  *
  * This content is released under the MIT License (MIT)
  *
- * Copyright (c) 2014 - 2019, British Columbia Institute of Technology
+ * Copyright (c) 2019 - 2022, CodeIgniter Foundation
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -30,6 +30,7 @@
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
  * @copyright	Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
+ * @copyright	Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/)
  * @license	https://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.0.0
@@ -46,7 +47,7 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  * @subpackage	Libraries
  * @category	Libraries
  * @author		EllisLab Dev Team
- * @link		https://codeigniter.com/user_guide/general/routing.html
+ * @link		https://codeigniter.com/userguide3/general/routing.html
  */
 class CI_Router {
 
@@ -57,6 +58,13 @@ class CI_Router {
 	 */
 	public $config;
 
+	/**
+	 * CI_URI class object
+	 *
+	 * @var	object
+	 */
+	public $uri;
+
 	/**
 	 * List of routes
 	 *
@@ -83,7 +91,7 @@ class CI_Router {
 	 *
 	 * @var	string
 	 */
-	public $directory;
+	public $directory = '';
 
 	/**
 	 * Default controller (and method if specific)
@@ -332,7 +340,7 @@ class CI_Router {
 	protected function _validate_request($segments)
 	{
 		$c = count($segments);
-		$directory_override = isset($this->directory);
+		$directory_override = $this->directory !== '';
 
 		// Loop through our segments and return as soon as a controller
 		// is found or when such a directory doesn't exist