Developer credits
Git commits in Moodle 2.6.6 by Pavel Sokolov
commit 9fd75edd911f4802726280a1987e25b386a3a2e1 Author: Pavel Sokolov <pavel.m.sokolov@gmail.com> Date: Wed, 24 Sep 2014 15:51:03 +0800 Tag: v2.6.6 MDL-37707 mod_assign: Prevent user from switching to and from team submissions