Author: Damyon Wiese
MDL-33600 Assign: Add an admin setting to set the default for sendstudentnotifications
http://git.moodle.org/gw?p=moodle.git;a=commit;h=8e1266bf773f6f47fa50af9be3714d3f2e7b0327
http://github.com/moodle/moodle/commit/8e1266bf773f6f47fa50af9be3714d3f2e7b0327
+ 2.7 en [sendstudentnotificationsdefault,mod_assign]
+ 2.7 en [sendstudentnotificationsdefault_help,mod_assign]