Author: David Monllao
MDL-31500 backup: Warn users about front page backups
They should know that they can only be restored on the front
page before selecting the destination course.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=99e434f2fa0afb28b770fb70b1fb96294c15824e
http://github.com/moodle/moodle/commit/99e434f2fa0afb28b770fb70b1fb96294c15824e
+ 2.9 en [sitecourseformatwarning,core_backup]