Author: Sara Arjona
MDL-61952 gradeexport_txt: Implement privacy API
http://git.moodle.org/gw?p=moodle.git;a=commit;h=c52427e1b8177aa9081f6cf942e62e45938bc428
http://github.com/moodle/moodle/commit/c52427e1b8177aa9081f6cf942e62e45938bc428
+ 3.4 en [privacy:metadata,gradeexport_txt]