Previously we only used these caches for Tornado requests, because we
were not updating memcached when e.g. the user's pointer changed, and
so functions like update_pointer would not work correctly.
Now that we are updated memcached when the User and UserProfile
objects change, we can use these for all requests.
This saves 2 database queries on every Django request to the server.
(imported from commit aa5bffd885d14bde38b95e80a226bd5ab66f253d)
This should substantially decrease the amount of server load generated
by the userpresence system.
I tested that this indeed was indeed saving one query on
/json/update_active_status requests on my laptop with 2 users from the
humbughq.com realm logged in.
(imported from commit 03e9d4eb95b9f664d489862684ae162db2076e08)
This should substantially improve the repeat-rendering time for pages
with large numbers of tweets since we don't need to go all the way to
twitter.com, which can take like a second, to render tweets properly.
To deploy this commit properly, one needs to run
./manage.py createcachetable third_party_api_results
(imported from commit 01b528e61f9dde2ee718bdec0490088907b6017e)
This allows us to handle the return_messages_immediately part of
get_updates requests without having to talk to the database.
(imported from commit ed0b7742d359efb21a0a4960f4fc25f4337e9ad4)
