* The `.Use` of storageHandler before setting up the template renderer
causes a panic if there is an error to log.
* The error passed to `ctx.Error` in that case may contain sensitive
information and should not be rendered to the end user. We should
instead log the error and render a simple error message.
* There is no handling of missing avatars and this needs a 404. Minio
errors need to be mapped to standard golang errors such as
os.ErrNotExist.
* There is no logging when storage is set up.
Related #13159
Signed-off-by: Andrew Thornton <art27@cantab.net>