Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Start the dreaded NOFOO -> NO_FOO conversion.

OK'ed by: core

Switch over to a different, more flexible test output protocol that's
understood by Perl's Test::Harness module and prove(1) commands.

Update README to describe the new protocol. The work's broken down into
two main sets of changes.

First, update the existing test programs (shell scripts and C programs)
to produce output in the ok/not ok format, and to, where possible, also
produce a header describing the number of tests that are expected to be
run.

Second, provide the .t files that actually run the tests. In some cases
these are copies of, or very similar too, scripts that already existed.
I've kept the old scripts around so that it's possible to verify that
behaviour under this new system (in terms of whether or not a test fails)
is identical to the behaviour under the old system.

Add a TODO file.

Join the effort in simplifying this makefile. ;)

Pass O_NONBLOCK directly to fcntl() rather than the pointer to an int
holding the value O_NONBLOCK. This worked previously because I was
lucky.

Don't override the rule used to build a binary by providing our own
compiler line.

Add a basic kqueue + UNIX domain socket pair regression test to do some
elementary exercising of kqueues on datagram and stream sockets. Note
that the datagram write kqueue case is left untested due to potentially
confusing behavior for the developer (me) that might require attention.