Author: Mark Nelson
MDL-30377 forum: do not allow users to view not yet started or expired discussions
http://git.moodle.org/gw?p=moodle.git;a=commit;h=edbada7c4f4a36f9b23bfd2020277a2c2f91b81a
http://github.com/moodle/moodle/commit/edbada7c4f4a36f9b23bfd2020277a2c2f91b81a
+ 2.2 en [forumbodyhidden,mod_forum]