This includes a hack to preserve humbug/backends.py as a symlink, so
that we don't need to regenerate all our old sessions.
(imported from commit b7918988b31c71ec01bbdc270db7017d4069221d)
If you entered "stream:Denmark " in the search box, we would show
you two suggestions for "stream Denmark", despite our duplicate
detection, because we didn't canonicalize the suggestion that is
literally based off the user typed query, and so the other way
of generating the "stream Denmark" suggestion created a duplicate.
Now all the suggestions we generate are canonicalized, so the
generalized duplicate detection can work.
(imported from commit 52bf08ccf9bb2e2260ca8c20690169aead3732ab)
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)