This fixes trac #1660. A deactivated user may still have the
active flag set to "true" on their subscriptions, but this is
just to help future reactivations; they are not actually
valid subscribers while deactivated, so we add UserProfile.is_active
to our filter in the query in get_subscribers_backend().
(imported from commit 8598b2e180faea618371293e42b794898e645004)
We need to be able to let a user through if they are trying to sign up
for a completely open realm like CUSTOMER3.
(imported from commit 1e33ab0ce94545f217739d501e9227dfb48e1123)
It will have new callers soon and that's as fine a place as any to
avoid circular imports.
(imported from commit 089a724e9ad06cb5a51ffe80f1729d789238e5f6)
This needs to be deployed to both staging and prod at the same
off-peak time (and the schema migration run).
At the time it is deployed, we need to make a few changes directly in
the database:
(1) UPDATE django_content_type set app_label='zerver' where app_label='zephyr';
(2) UPDATE south_migrationhistory set app_name='zerver' where app_name='zephyr';
(imported from commit eb3fd719571740189514ef0b884738cb30df1320)
