Previously, the "theme cookie tween" was setting the theme cookie on
every single GET request, in order to make sure that the domain was set
on it so that it would be accessible from the Blog and Docs sites. We've
been doing this for a long time now though, and almost every cookie
should have been set properly now.
Now, this tween will only set the cookie when it's actually necessary -
when the user is logged-in and has a default theme, but doesn't already
have a theme cookie.
Deimos
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