obfsproxy's SOCKS server should support more SOCKS failure replies
The SOCKS5 standard defines: o REP Reply field: o X'00' succeeded o X'01' general SOCKS server failure o X'02' connection not allowed by ruleset o X'03' Network unreachable o X'04' Host unreachable o X'05' Connection refused o X'06' TTL expired o X'07' Command not supported o X'08' Address type not supported o X'09' to X'FF' unassigned our obfsproxy src/socks.c currently only supports X'00' and X'01'. We should add support for the rest.