Handle cookies (non-persistently)

In a load-balanced environment, correctly handling the 'exchangecookie'
cookie is important because it is used to preserve server affinity, and
certain operations which require server-based state will fail without it.

http://blogs.msdn.com/b/exchangedev/archive/2011/07/20/client-access-server-affinity-and-network-load-balancing-considerations-for-programmatic-access-to-exchange-online.aspx
https://bugzilla.gnome.org/show_bug.cgi?id=732850#c70

(cherry picked from commit 73914e5ee549638056fce5d54a6714988b1b4f8a)