All Promise objects were passed to force_text() deep in ORM query code.
Not only does this make it difficult or impossible for developers to
prevent or alter this behaviour, but it is also wrong for non-text
This commit changes `Field.get_prep_value()` from a no-op to one that
resolved Promise objects. All subclasses now call super() method first
to ensure that they have a real value to work with.
The documentation promises that host validation is disabled when
DEBUG=True, that all hostnames are accepted. Domains not compliant with
RFC 1034/1035 were however being validated, this validation has now been
removed when DEBUG=True.
Additionally, when DEBUG=False a more detailed SuspiciousOperation
exception message is provided when host validation fails because the
hostname is not RFC 1034/1035 compliant.