three hacks to workaround bug 1038
The problem is that clients and hidden services are receiving relay_early cells, and they tear down the circuit. Hack #1 is for rendezvous points to rewrite relay_early cells to relay cells. That way there are never any incoming relay_early cells. Hack #2 is for clients and hidden services to never send a relay_early cell on an established rendezvous circuit. That works around rendezvous points that haven't upgraded yet. Hack #3 is for clients and hidden services to not tear down the circuit when they receive an inbound relay_early cell. We already refuse extend cells at clients.