Author: Mark Nelson
MDL-63466 core_message: deprecated methods and services
http://git.moodle.org/gw?p=moodle.git;a=commit;h=d1e8e69d8579f9075e917760e9f709d214ab305c
http://github.com/moodle/moodle/commit/d1e8e69d8579f9075e917760e9f709d214ab305c
+ 3.6 en [conversationdoesntexist,core_message]