Git commits in Moodle 3.3.0 by Tim Lock

commit 32a7986422e09ef653c7efd6aa461edbd30c2605
Author: Tim Lock <tim@netspot.com.au>
Date:   Tue, 17 Jan 2017 09:50:26 +0800
Tag:    v3.3.0-beta

MDL-57668 mod_assign: Fix optional_param() form processing