Author: Andrew Nicols
MDL-77186 admin: Add min/max limits to configduration
http://git.moodle.org/gw?p=moodle.git;a=commit;h=097d2bda6c618cc3781b5f02dbdb25060fb83d5e
http://github.com/moodle/moodle/commit/097d2bda6c618cc3781b5f02dbdb25060fb83d5e
+ 4.2 en [configduration_low,core_admin]
+ 4.2 en [configduration_high,core_admin]