Author: Rossiani Wijaya
MDL-24258: eliminate student capability to delete their post when it exceeded the max editing time.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=c927eb443e653019ed2441336fbac7c9f08d121b
http://github.com/moodle/moodle/commit/c927eb443e653019ed2441336fbac7c9f08d121b
+ 1.9 en [cannotdeletepost,mod_forum]