Real names instead of user names used for placeholders

Created by: atrol

Placeholders for users are replaced by the real name instead of the user name if the following configuration is used and the access level of the current user is >= $g_show_user_realname_threshold

$g_show_realname = ON;
$g_show_user_realname_threshold = DEVELOPER;

When using such a snippet, real names are published to any user, even those who are not allowed to view real names.