Author: Jake Dallimore
MDL-63724 core_message: add send_message_to_conversation() to manager
http://git.moodle.org/gw?p=moodle.git;a=commit;h=9581bc3c00db139f630f6ccef25a15c8cd1c2b9c
http://github.com/moodle/moodle/commit/9581bc3c00db139f630f6ccef25a15c8cd1c2b9c
+ 3.6 en [unreadnewgroupconversationmessage,core_message]