Display gravatars on profiles

Partially addresses #909 but does not fully resolve it.
Adds some stuff relevant to #911.

http://jenkins.buttonweavers.com:8080/job/buttonmen-AdmiralJota/192/

Dependent on #1068.
seems like this email_hash field is added to the live return value of get_profile_info(), but wasn't added to the dummy responder value.