Git commits in Moodle 3.8.0 by Ilya Tregubov

commit 64ce596f8c0561cbe365b770058c8f7dbe49d2f8
Author: Ilya Tregubov <ilyatregubov@catalyst-au.net>
Date:   Mon, 17 Jun 2019 13:37:32 +0800
Tag:    v3.8.0-beta

MDL-65925 assign: Grade page broken if submission was deleted.

commit 4120908e1900d81a579ff58ce138aff42931f3f4
Author: Ilya Tregubov <ilyatregubov@catalyst-au.net>
Date:   Wed, 03 Apr 2019 13:47:52 +0800
Tag:    v3.8.0-beta

MDL-65249 Session: Throw exception if number of attempts exceeded.