Author: Marina Glancy
MDL-60742 calendar: allow customisation of 12/24h time format strings
http://git.moodle.org/gw?p=moodle.git;a=commit;h=505de3307c8973141229991d241180e07b3fe7ad
http://github.com/moodle/moodle/commit/505de3307c8973141229991d241180e07b3fe7ad
+ 3.3 en [strftimetime12,core_langconfig]
+ 3.3 en [strftimetime24,core_langconfig]