The XSRF token is now encoded with a random mask on each request.
This makes it safe to include in compressed pages without being
vulnerable to the BREACH attack.
This applies to most applications that use both the xsrf_cookies
and gzip options (or have gzip applied by a proxy).
If Tornado 3.2.2 is run at the same time as older versions on the same
domain, there is some potential for issues with the differing cookie
versions. The .Application setting xsrf_cookie_version=1 can
be used for a transitional period to generate the older cookie format
on newer servers.
tornado.platform.asyncio is now compatible with trollius version 0.3.