Author: Laurent David
MDL-76551 mod_bigbluebuttonbn: Add user picture
* Add user picture with token
* Add a new global setting to enable or disable avatar for users in meeting.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=aa9c5cf455a35393f8a0eb386f1873134329c857
http://github.com/moodle/moodle/commit/aa9c5cf455a35393f8a0eb386f1873134329c857
+ 4.2 en [config_profile_picture_enabled,mod_bigbluebuttonbn]
+ 4.2 en [config_profile_picture_enabled_description,mod_bigbluebuttonbn]