[ticket/12597] Fix various problems

Actually fix the return status of command cron:run-all
Fix some doc block coding style issue
Fix missing and obsolete file headers
Delete a useless constructor method

PHPBB3-12597

tests/console/cron/tasks/simple.php

@@ -1,13 +1,19 @@
 <?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited 
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
 
 class phpbb_cron_task_simple extends \phpbb\cron\task\base
 {
-	public $executed;
-
-	public function __construct()
-	{
-		$this->executed = false;
-	}
+	public $executed = false;
 
 	public function get_name()
 	{