Git commits in Moodle 3.8.0 by Huong Nguyen

commit 0fd6032ce820c1fe2ecf464d2bfe399a7ed29ff0
Author: Huong Nguyen <huongnv13@gmail.com>
Date:   Thu, 19 Sep 2019 11:56:36 +0800
Tag:    v3.8.0-beta

MDL-66633 Quiz: Improve preview user checking

commit 8dc015050e638887bce8d7e6827dcfe8c0ef1fd2
Author: Huong Nguyen <huongnv13@gmail.com>
Date:   Mon, 09 Sep 2019 15:55:39 +0800
Tag:    v3.8.0-beta

MDL-66633 quiz: allow to create attempts for different users

commit afcc7a723d14bf5d89a395fd58179f317a9b0c2d
Author: Huong Nguyen <huongnv13@gmail.com>
Date:   Wed, 26 Jun 2019 15:57:02 +0800
Tag:    v3.8.0-beta

MDL-64258 Group: Performance problem on the enrol group members page

commit 53f796b91accb63334082096b23d84ade66d2c63
Author: Huong Nguyen <huongnv13@gmail.com>
Date:   Wed, 26 Jun 2019 15:19:51 +0800
Tag:    v3.8.0-beta

MDL-64258 Group: Unit Test for find_users function

commit 0fc30827dce3d6373959b7fc28ce27d1e5dbf825
Author: Huong Nguyen <huongnv13@gmail.com>
Date:   Thu, 13 Jun 2019 15:49:20 +0800
Tag:    v3.8.0-beta

MDL-64032 enrol_manual: Make consistent the UI for setting enrolment