Bump version number, update release notes, rename release notes and tweak
markup. Update copyright year.

Updates version numbers, release notes, etc.

* EXIT_SUCCESS and EXIT_FAILURE are defined in stdlib.h, not sysexits.h
so no need to include the latter.

* No need to include pthread.h.

* Remove the no longer used delay() function.
This also removes the reliance on nanosleep().

* Remove get_tcp_windowsize() and set_tcp_windowsize() which are unused.
These days, iperf uses get/setsockopt() with SO_SNDBUF SO_RCVBUF directly.

* Add configurable timeout for the setup of the control connection.
This is specified using the new --connect-timeout option, with an
integer parameter in ms.  The iperf3 client will wait for this
amount of time for the setup of the control connection to the
server.  If this option is not given, the OS default for TCP
connection setup is used.  Specifying a smaller connection timeout
allows faster detection of a down / unresponsive iperf3 server.

The implementation uses a variation on the timeout_connect()
function from OpenBSD's netcat utility.

Fixes #216.

Note that the license remains a 3-clause BSD license; the only
license changes were to add the name of the program and to add
some punctuation.

UDP tests store a packet sequence number in the packets to detect loss
and ordering issues.  This sequence number is a 32-bit signed integer,
which can wrap during very long-running UDP tests.  This change adds
an option (defaulting to off) which uses a 64-bit unsigned integer to
store this quantity in the packet.  The option is specified on the
client side; the server must support this feature for proper
functioning (older servers will interoperate with newer clients, as
long as --udp-counters-64-bit is not used).

The default might be changed in a future version of iperf3.

As a part of this change, the client sends its version string to the
server in the parameter block.

Uses a public-domain compatibility shim for 64-bit byte order
conversions.  There are probably some additional platforms that need
to be supported, in particular Solaris.  We might add some
configure-time checks to only enable this feature on platforms where
we can support the byte-order conversions.

This change is not well-tested.

Towards issue #191.

git-subtree-dir: docs/_esnet
git-subtree-split: c02bf57d43dbfcd7c727cdd17c54f0a480279f9a