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=62897237f726488546eedfe2b368bb89ba4bab58
http://github.com/moodle/moodle/commit/62897237f726488546eedfe2b368bb89ba4bab58
+ 2.8 en [firstdayofweek,core_langconfig]