Author: Andrew Nicols
MDL-47390 mod_forum: Add discussion unsub to email footer
http://git.moodle.org/gw?p=moodle.git;a=commit;h=4e3af3cf4207dcc4cd54c8ed2e0f3d7f6fd592c1
http://github.com/moodle/moodle/commit/4e3af3cf4207dcc4cd54c8ed2e0f3d7f6fd592c1
+ 2.8 en [unsubscribediscussion,mod_forum]