Author: Mark Nelson
MDL-49359 install: warn against using MyISAM
http://git.moodle.org/gw?p=moodle.git;a=commit;h=3c2c8a0628ca359f203635cc3e0c9e11a31735a9
http://github.com/moodle/moodle/commit/3c2c8a0628ca359f203635cc3e0c9e11a31735a9
+ 2.8 en [unsupporteddbstorageengine,core_admin]