Author: Frederic Massart
MDL-18301 Gradebook: Added feature for components to control grade visibility
http://git.moodle.org/gw?p=moodle.git;a=commit;h=455dc0de61ac6845a0028369e9a9f2d2ea0945c4
http://github.com/moodle/moodle/commit/455dc0de61ac6845a0028369e9a9f2d2ea0945c4
+ 2.4 en [componentcontrolsvisibility,core_grades]