Git commits in Moodle 2.8.x by Pavel Sokolov

commit 5ae56c6e44436d6fe42d2e3eba354d1c5c9e564d
Author: Pavel Sokolov <pavel.m.sokolov@gmail.com>
Date:   Wed, 24 Sep 2014 15:51:03 +0800
Tag:    v2.8.0-beta

MDL-37707 mod_assign: Prevent user from switching to and from team submissions