* [Gravatar/Profiles] Gravatar icons will now only be displayed on worker and group profiles if the Gravatar plugin is enabled.  This addresses a conflict of interest for Cerb users who compete with Wordpress.
* [Mail/ACL/Usability] When a worker moves a ticket from its profile page into a group they are not a member of, they will now be redirected to their default page rather than being shown a cryptic "Access denied" error page.
Merge branch '6.4.3' into stable