* begin adding better fuzz test
* finish adding working fuzzer
* implement mutateipv4
* fuzzer finds a panic in ICMP client on receive empty payload
* rename fuzz tests to reflect fuzz methodology
* begin adding icmp client
* rely on anon structs
* add tests
* tests passing
* icmp fleshed out
* rework icmp to include ip addr
* rename StackAsync.Demux/Encapsulate to RecvEthernet and SendEthernet
* remove legacy unreachable TCP tests
* remove uses of deprecated internet.StackNode in preference of lneto.StackNode
* documentation
* rename methods to signal no I/O happening
* fix for #58
* add fixes for both retransmit and fuzz failure found
* fix infinite challenge ack due to RST+SYN+FIN corrupt packet in SYNRCV state
* fuzz: previous recovery ack path led to infinite transmit
* fuzz: calculate CRCs when fuzzing to reduce search space to non-CRC error cases
* add local fuzz corpus to tests
* add more cases to fuzz corpus
Pat Whittingslow