This is a preparatory commit for using isort for sorting all of our
imports, merging changes to files where we can easily review the
changes as something we're happy with.
These are also files with relatively little active development, which
means we don't expect much merge conflict risk from these changes.
This adds a medium (500px) size avatar thumbnail, that can be
referenced as `{name}-medium.png`. It is intended to be used on the
user's own settings page, though we may come up with other use cases
for high-resolution avatars in the future.
This will automatically generate and upload the medium avatar images
when a new avatar original is uploaded, and contains a migration
(contributed by Kirill Kanakhin) to ensure all pre-existing avatar
images have a medium avatar.
Note that this implementation does not provide an endpoint for
fetching the medium-size avatar for another user.
[substantially modified by tabbott]
Tim Abbott
rht
Aditya Bansal
Rick Chern
Brock Whittaker