Author: Andrew Nicols
MDL-48309 mod_forum: Add discussion subscription to the navigation
http://git.moodle.org/gw?p=moodle.git;a=commit;h=da9d46b5c049fb7e00e874fd34bb626b3c479713
http://github.com/moodle/moodle/commit/da9d46b5c049fb7e00e874fd34bb626b3c479713
+ 2.8 en [confirmsubscribediscussion,mod_forum]
+ 2.8 en [confirmunsubscribediscussion,mod_forum]
+ 2.8 en [subscribediscussion,mod_forum]