Profiles: Display GitHub activity on profiles.
This is implemented through a WordPress GitHub organization webhook, which parses pushed events and stores it in a table for later querying.
This is how Trac/SVN (and now GitHub) activity is inserted into the profiles activity stream.
Issues created & closed, Pull Requests submitted & merged, and pushes to repositories are supported.
Activity is only recorded against a WordPress.org profile if their GitHub profile is linked to WordPress.org, but will show up once that's done.
This is still a work in progress, and we may want to import older history as well.
See #4447, #5592.