Backport client handling for END_STREAM_REASON_NOROUTE
0.2.1.x Tor clients should handle the new reason 8: NOROUTE correctly by retrying it. See the commits merged in Sebastian's misc-reason branch, plus Roger's 4c948ffd6.
This is worth backporting because these errors happen not infrequently, and if the exit has a bad network configuration, clients really should retry the stream.