Author: Dan Poltawski
MDL-51651 lang: the first day of the week is Monday
http://git.moodle.org/gw?p=moodle.git;a=commit;h=316f8231f861f204f9474cc33be32a8062f4e95c
http://github.com/moodle/moodle/commit/316f8231f861f204f9474cc33be32a8062f4e95c
+ 3.0 en [firstdayofweek,core_langconfig]