Git commits in Moodle 1.7.4 by pichetp

commit 9a94ae5494e523e155251a576d4f86116bf37784
Author: pichetp <pichetp>
Date:   Thu, 01 Nov 2007 09:40:01 +0900
Tag:    v1.7.4

MDL-11867 setting real null when response is null in calculated question merged from  head