Author: Amaia Anabitarte
MDL-72919 core_course: Improve add weeks styling
http://git.moodle.org/gw?p=moodle.git;a=commit;h=6e089b26023f0e1fc14c78ab06fee8a6c81d3175
http://github.com/moodle/moodle/commit/6e089b26023f0e1fc14c78ab06fee8a6c81d3175
+ 4.0 en [addsections,format_topics]