Configurable timezone

[jtdroste]

Hi,
How about we add configurable timezone to this script? Instead of relying on the host's timezone configuration, that is. I feel this should be a simple addition, all you would need to do is:

1. Modify settings.php to include a section called timezone. Put all the timezones in there (get it from timezone_identifiers_list)

2. When writing to config.php, add date_default_timezone_set('$_POST['timezone']'); to the top of it