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.
Does a database migration to rename Realm.subdomain to
Realm.string_id, and makes Realm.subdomain a property. Eventually,
Realm.string_id will replace Realm.domain as the handle by which we
retrieve Realm objects.
Tim Abbott
Anders Kaseorg
rht
Rishi Gupta