* Stop setting a shortcode to newly-created media attachments
The WebUI has stopped using the “short media URL” in ages. This isn't used
anywhere except for mail notifications.
Deprecating it would allow us to eventually get rid of at least a database
column and corruption-prone index, as well as a controller.
* Fix tests
* Add render_views in more places
* Delegate methods from account to user with allow nil true, so that admin accounts show view renders when missing a user
* Use actual account instances in authorize follow controller spec
