the nsupdate.info zone is configured to allow updating test.nsupdate.info with a non-secret key used for the tests.
we also have a test that tries to update another host with that key and checks that this fails.
change the tests so they only use test.nsupdate.info (if possible).
single-host update secrets need a Domain record for the fqdn of this single host, the fqdn is tried first, before it tries the origin zone.
"public" field means that this zone can be used by every user (not just the owner) to create hosts there
"available" field means that the nameserver is operating and reachable
remove unneeded stuff from settings
(we still need some in conftest.py for the tests, though)
init DB for tests via conftest.py
more update algorithm choices
give origin zone (if we already know it) to dnstools functions
new views: DomainOverview, DeleteDomain
unify deletion templates using delete_object.html
add django-extensions
