* remove old fuzz corpus and stick to using PCG for seeding fuzz test
* polish up drain logic and reduce action search space
* improve fuzzing debug prints
* more fuzz fixes also formatter capture printer fixes
* refactor StackSeeded test
* fix challenge ack infinite packet bug
* more expressive challenge satisfy
* remove printing
* tcp: remove retransmit logic entirely; add duplicate ack counting to ControlBlock
* retransmit implemented in nice simple straightforward way
* narrow down retransmission cases
* remove old timing tests
* add ControlBlock retransmit test
* add failing handler test
* reworking payload length semantic meaning in code
* fix establish conn logic
* clean up tests and add TCB dupack generation and test it
* catch pending retransmit satisfy in test
* add fuzz test for control block
* bugfix: be more strict in what is considered dupack
* add IncomingIsDupACK docs
* limit queue of retransmits
* protect retransmit overflow from incorrectly updating nxt
* tcp: bugfix for seq not in snd/rcv.wnd error
* accept dupe ACKs for window updates and prevent decrement of UNA
* add fixes for incorrect tcp functioning
* remove Conn.Available* methods in favor of Conn.Free* methods due to ambiguous name