Author: Aya Saad
MDL-74379 language: injecting am/pm in date string
patching the date_format_string() function in moodlelib to add am/pm for languages that don't suuport it.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=df32c00ab50b00cde624130ac9831f1f9bfb8336
http://github.com/moodle/moodle/commit/df32c00ab50b00cde624130ac9831f1f9bfb8336
+ 3.11 en [am,core_langconfig]
+ 3.11 en [amcaps,core_langconfig]
+ 3.11 en [pm,core_langconfig]
+ 3.11 en [pmcaps,core_langconfig]