Git commits in Moodle 2.9.7 by Marina Glancy

commit 67889ed5be642d44687cd3bc2f8a15ba3ee39860
Author: Marina Glancy <marina@moodle.com>
Date:   Mon, 04 Jul 2016 10:32:20 +0800
Tag:    v2.9.7

MDL-55069 core: escape special characters in email headers