Change the logging file name set

The date part is not set external, but internal via a flag.
The file name extension cannot be set anymore and the file_name_ext has
been removed and is now log_file_name_ext and privte.

This is a drop in solution and can be used with previous settings.

Changes that should be done:
Class.Login: remove the file name ext and replace it with log_per_class
= 1
Remove all file_name_ext entries as they area not needed anymore

www/admin/header.inc

@@ -56,8 +56,6 @@
 	$smarty = new SmartyML($lang);
 	// create new DB class
 	$cms = new AdminBackend($DB_CONFIG[MAIN_DB], $lang);
-	// set daily rotation
-	$cms->file_name_ext = '_'.date('Y-m-d').'.log';
 	// set search path to the default DB schema
 	$cms->db_exec("SET search_path TO ".DB_SCHEMA);
 	// the menu show flag (what menu to show)