Git merges in Moodle 2.6.4 by AMOS bot

commit eb4b4c7ba094668f43b2e8fc86900e873465d53a
Author: AMOS bot <amos@moodle.org>
Date:   Fri, 13 Jun 2014 08:42:09 +0800
Tag:    v2.6.4

Merge branch 'MOODLE_26_STABLE' into install_26_STABLE