There seems to be some sort of bug involving PhantomJS and XHR
streaming messages. When successive pages are loaded that use XHR
streaming, PhantomJS seems to think the second one never finishes
loading and therefore hangs.
(imported from commit db93b4cab816f1fdc3f3f543c9394b1cba8abedb)
Because our authentication system reads cookies from the initial
connection attempt, several SockJS transports can't be used.
(imported from commit 34b9571225d39072985b8223fb12c43c7235841f)