Link to gravatar image is generated completely on client-side and no
longer included into user or record objects.
Added libs:
* JS MD5 (BSD license)
* JS jQuery.gravatar (WTFPL license), changed
Removed libs:
* Flask.Gravatar
Closes bug 1320242
Change-Id: Iee08dc845c162a3ccb97d176997df31a6e7b3c63