Move to version 2.9.1
Copy input string to a temporary buffer before calling strtok_r in scan_tcp_port

Otherwise things will break earlier.  Also improve the errror handling of
scan_tcp_port so it can return ENOMEM if necessary.
Improve IPV6 handling

* utils.c, utils.h, dataxfer.c, controller.c: Rework the handling
of addresses to work properly with all the return values of
getaddrinfo, and to prefer IPV6 over IPV4 when opening the socket.
This means if you specify a number, it will open the IPV6 ::,port
address first.  This was a big cleanup, and moved a lot of the
base socket handling into utils.h.

* dataxfer.c: Rework the stdio handling so it doesn't rely on the
port number in the address, since that is now gone.

* dataxfer.c: Set port->closestr to NULL when freeing it to avoid
a double-free.

* readconfig.c, ser2net.8: Rework the input handling so an IPV6
can be specified as part of the portnum parameter.  This was hard
because IPV6 addresses have ':' in them.  Basically, if there is a
"," in the port specification, assume that everything from the
beginning of the line to the ':' after the ',' is the port number.
Open all addresses returned by getaddrinfo

* utils.c, utils.h, dataxfer.c, controller.c: Modified address
handling so that ser2net opens all the addresses returned by
getaddrinfo, not just the first one.  That should make things
work correctly in a lot more cases.
merge upstream commits

port->acceptfd has been changed to port->acceptfds, but only one could
be handled in rraw mode by now.