Tidy up logging and authentication settings
Add login and logout functionality
Ignore editor files and the logs directory
Clarify what the resulting queryset may look like
Add a function to check whether a user is a pilot
Add middleware to patch the built-in User model

Because we're making use of the built-in User model for pilots, we need a way
of determining whether a given user is a pilot or not. Providing util.is_pilot
is a good way to start, but it would be more useful if we could query User
instances directly (e.g. particularly in templates). This middleware sets a new
callable on all User instances: is_pilot(self)
Show header links appropriate to the current user

* Superusers are the only users who see the admin site
* Pilots and superusers are the only users who may make updates to checkouts
Create template for 403 Forbidden responses
Set init data and enforce user restrictions

* When a pilot visits the Add/Remove page, their name should be pre-selected.
* Only pilots and superusers may edit checkouts. Since the header link to the
Add/Remove page only appears for the above user categories, these checks are a
secondary line of defense to prevent 'accidents' from copy/pasted URLs and
malicious form submissions.
* Pilots may only add/remove checkouts attached to their own account.