Author: Petr Škoda
MDL-35289 add missing charmap usage info string
http://git.moodle.org/gw?p=moodle.git;a=commit;h=9cd1f8ffe6be474f95e6f5247c7dc14f0379e288
http://github.com/moodle/moodle/commit/9cd1f8ffe6be474f95e6f5247c7dc14f0379e288
+ 2.3 en [advanced_dlg:charmap_usage,editor_tinymce]