Author: Damyon Wiese
MDL-40759 fontawesome: Use a cache
Cache the callback info.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=7e8940b544871b186c0fbe6ac5a8458b824dffd6
http://github.com/moodle/moodle/commit/7e8940b544871b186c0fbe6ac5a8458b824dffd6
+ 3.3 en [cachedef_fontawesomeiconmapping,core_cache]