Author: Mihail Geshoski
MDL-72873 core_grades: Add tertiary navigation in grade scales
http://git.moodle.org/gw?p=moodle.git;a=commit;h=eb0b022bb7ab31add15c311d39ecd5ad6bf5fd26
http://github.com/moodle/moodle/commit/eb0b022bb7ab31add15c311d39ecd5ad6bf5fd26
+ 4.0 en [noexistingscales,core_grades]