Git commits in Moodle 3.1.0 by Nicholas Hoobin

commit c5211882f79b12f89310779048ec9cf71ea7a678
Author: Nicholas Hoobin <nicholashoobin@catalyst-au.net>
Date:   Mon, 18 Apr 2016 14:28:45 +0800
Tag:    v3.1.0-beta

MDL-53599 session: Added a session_class_handler for Redis.