Author: Eric Merrill
MDL-48618 gradebook: Only use individual min/max for aggrigate grades
http://git.moodle.org/gw?p=moodle.git;a=commit;h=582d2448b5e289cd340dc01b3b086cf789c4fc45
http://github.com/moodle/moodle/commit/582d2448b5e289cd340dc01b3b086cf789c4fc45
+ 2.8 en [minmaxupgradedgrades,core_grades]
+ 2.8 en [minmaxupgradefixbutton,core_grades]
+ 2.8 en [minmaxupgradewarning,core_grades]
+ 2.8 en [upgradedminmaxrevertmessage,core_grades]