- updated all code to use the request class instead of any direct access to

super globals
- disabled super globals in common.php. See commit r9101 for
  more information
- cleaned up/simplified a few lines along the way.

git-svn-id: file:///svn/phpbb/trunk@9102 89ea8834-ac86-4346-8a33-228a782c2dd0

phpBB/includes/db/dbal.php

@@ -632,7 +632,7 @@ class dbal
 	{
 		global $cache, $starttime, $user;
 
-		if (empty($_REQUEST['explain']))
+		if (!request::variable('explain', false))
 		{
 			return false;
 		}