Author: David Monllao
MDL-29563 course Hide duplication button in activities without backup2 support - Credit to Mark Nielsen
http://git.moodle.org/gw?p=moodle.git;a=commit;h=8a1a951f7c77bf997256044eba67fb38b5ea33c9
http://github.com/moodle/moodle/commit/8a1a951f7c77bf997256044eba67fb38b5ea33c9
+ 2.4 en [duplicatenosupport,core]