1) The class Filter now lives in its own module.
2) The function canonicalized_operators() is now a class method on Filter.
3) The function message_in_home moved to filter.js and became private.
4) Various calling code had to change, of course.
5) Splitting out Filter helped simplify a few tests.
(imported from commit e41d792b46d3d6a30d3bd03db0419f129d0a2a7b)
There are also one or two places we don't need to use it for security
purposes, but we do so for consistencey.
(imported from commit aa111f5a22a0e8597ec3cf8504adae66d5fb6768)
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)