Git commits in Moodle 2.3.9 by Eloy Lafuente (stronk7)

commit 090a5f635d8061d5cda0c6e3f99dd4fab7e10094
Author: Eloy Lafuente (stronk7) <stronk7@moodle.org>
Date:   Fri, 06 Sep 2013 17:20:19 +0800
Tag:    v2.3.9

MDL-41623 ensure all links are valid urls