Author: Huong Nguyen
MDL-73854 Calendar: Fix calendar controls cannot be translated
Fix the issue that calendar page and block are showing only English names
of next and previous months despite switching the language
http://git.moodle.org/gw?p=moodle.git;a=commit;h=46bbf6e74b7c4ae51e2b185862c83fbc0fbae97a
http://github.com/moodle/moodle/commit/46bbf6e74b7c4ae51e2b185862c83fbc0fbae97a
+ 4.0 en [strftimemonth,core_langconfig]