[new release] tcpip (7.1.2)
[new release] tcpip (7.1.2)

CHANGES:

* TCP: fix memory leaks on connection close in three scenarios (mirage/mirage-tcpip#489 @TheLortex)
  - simultanous close: set up the timewait timer in the `Closing(1) - Recv_ack(2) -> Time_wait`
    state transition
  - client sends a RST instead of a FIN: enable sending a challenge ACK even when the reception
    thread is stopped
  - client doesn't ACK server's FIN: enable the retransmit timer in the `Closing(_)` state

pirbo/opam-repository,fpottier/opam-repository,pqwy/opam-repository,codinuum/opam-repository,Leonidas-from-XIV/opam-repository,pirbo/opam-repository,nberth/opam-repository,jhwoodyatt/opam-repository,kkirstein/opam-repository,pqwy/opam-repository,Leonidas-from-XIV/opam-repository,codinuum/opam-repository,ocaml/opam-repository,ocaml/opam-repository,jhwoodyatt/opam-repository,kkirstein/opam-repository,fpottier/opam-repository,nberth/opam-repository