More Torbutton hangs on New Identity control port access

skruffy is reporting hangs on Torbutton's New Identity. Oddly, the hangs seem to be more common if you are loading a bunch of websites at the time of hitting New Identity, but that is not a full repro case.

The hang actually appears to be happening while attempting to open a control port connection. Perhaps another race introduced by our SOCKS optimistic data hack in nsITransport? Or perhaps our hack for #8642 (closed) is insufficient in some cases, and/or during heavy network activity.