Git commits in Moodle 1.6.8 by skodak

commit 1899c6567a36e13e5ae3f94a90523e3efea0af4a
Author: skodak <skodak>
Date:   Sat, 26 Jul 2008 06:46:33 +0800
Tag:    v1.6.8

MDL-15823 format_string() improvements; merged from MOODLE_19_STABLE