Developer credits
Git commits in Moodle 2.5.9 by David Monllao
commit 48ea41c48f3dcf28fb40fe0b0a1f0c4c0453d34d Author: David Monllao <davidm@moodle.com> Date: Wed, 29 Oct 2014 14:30:19 +0800 Tag: v2.5.9 MDL-47924 mod_lti: Fixing missing sesskey checking