Remove $FreeBSD$: one-line sh pattern

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

pkgbase: resolve mailer.conf conflict WITHOUT_SENDMAIL

When WITHOUT_SENDMAIL is set, we end up with two different mailer.conf that
conflict, and hilarity ensues. There's currently three different places that
we might install mailer.conf:

- ^/etc/Makefile (package=runtime, contingent on MK_MAIL != no)
- ^/libexec/dma/dmagent/Makefile (package=dma, contingent on MK_SENDMAIL !=
no)
- ^/usr.sbin/mailwrapper/Makefile (package=utilities, contingent on
not-installed)

The mailwrapper installation will effectively never happen because the ^/etc
one will first.

This patch simplifies the whole situation; remove the ^/etc/Makefile version
and install it primarily in mailwrapper if MK_MAILWRAPPER != "no". The
scenarios covered in mailwrapper are:

- sendmail(8) is installed, dma(8) may or may not be installed
- neither sendmail(8) nor dma(8) is installed

In the first scenario, sendmail(8) is dominant so we can go ahead and
install the version in ^/etc/mail. In the unlisted scenario, sendmail(8) is
not installed but dma(8) is, we'll let ^/libexec/dma/dmagent do the
installation. In the second listed scenario, we still want to install an
example mailer.conf so just install the base sendmail(8) version.

Reviewed by: bapt
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D24924

Replace send-mail with the more standarized sendmail, we do not create
links for send-mail in mailwrapper so it did not work anyway.

MFC after: 2 weeks

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.

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

Add the missing hoststat and purgestat commands. These are normally
symlinks to the sendmail binary but in FreeBSD's case, they are
symlinks to mailwrapper.

Submitted by: tisco
MFC after: 4 days

Add $FreeBSD$

Import NetBSD's mailwrapper to redirect /usr/sbin/sendmail to the user's
chosen mailer.

Obtained from: NetBSD