Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

Add -M option to nc(1), which makes it print the TCP connection
statistics obtained with stats(3) in JSON format to standard error.

Reviewed by: allanjude, thj, cem (earlier version)
Tested by: thj
MFC after: 2 weeks
Relnotes: yes
Sponsored by: Klara Inc.
Differential Revision: https://reviews.freebsd.org/D21324

Adopt SRCTOP in usr.bin

Prefer ${SRCTOP}/foo over ${.CURDIR}/../../foo and ${SRCTOP}/usr.bin/foo
over ${.CURDIR}/../foo for paths in Makefiles.

Differential Revision: https://reviews.freebsd.org/D9932
Sponsored by: Netflix
Silence on: arch@ (twice)

Convert to usr.bin/ to LIBADD
Reduce overlinking

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

Build usr.bin/ with WARNS=6 by default.

Also add some missing $FreeBSD$ to keep svn happy.

- Import the HEAD csup code which is the basis for the cvsmode work.

Fix bugs in the previous commit.

Revamp several Makefile nits:
- .PATH: is spelled ``.PATH: ''
- Don't forget to use DPADD so ``make checkdpadd'' is
not broken.
- LDADD should not come with + as it's empty in the
first place

Suggested by: ru

Finish the import of nc(1) from OpenBSD. This includes:
- Bring IPsec support from the ports collection [1].
- Bring -o ("once only") option from the ports
collection [2].
- Adopt the Makefile framework into
usr.bin/nc/Makefile.
- Add a knob to control whether to build nc(1),
NO_NETCAT.
- Bump __FreeBSD_version so ports collection can
detect this change.

Original patchset are contributed to the ports collection by:
[1] nectar, [2] joerg.

Note: WARNS?=6 patchset spined off in this commit, in order not
to take too many files off the vendor branch.