Author: Ryan Wyllie
MDL-63303 message: fix bugs in message drawer part 4
* Add clarification to delete messages lang strings
* Stop message polling when sending a message to fix UI bug
* Publish update last message event when polling finds more messages
* Remove logged in user from group conversation participants list
* Use user object to fetch user preferences to reduce DB calls
* Remove animated slide transitions because the browser breaks when
showing some conversations
http://git.moodle.org/gw?p=moodle.git;a=commit;h=d3d95d5dc2a8fa4895cf432109b52e58848911dc
http://github.com/moodle/moodle/commit/d3d95d5dc2a8fa4895cf432109b52e58848911dc
+ 3.6 en [deleteallconfirm,core_message]
+ 3.6 en [deleteselectedmessagesconfirm,core_message]
+ 3.6 en [otherparticipants,core_message]