Remove # $FreeBSD$ from Makefiles.

- Update OpenSMTPd to 6.6.0 portable release
    This release builds with LibreSSL > 3.0.2 or OpenSSL > 1.1.0.
    FreeBSD 11.x users should update to 12.x/13.x or switch system-wide
    default ssl library to openssl111/libressl

- Update -extras to 6.4.0 release
    Filters still missing, corresponded ports temporary markes
    as IGNORED

PR:		213442,228937
MFH:		2019Q4

Bump PORTREVISION for ports depending on the canonical version of GCC
as defined in Mk/bsd.default-versions.mk which has moved from GCC 8.3
to GCC 9.1 under most circumstances now after revision 507371.

This includes ports
 - with USE_GCC=yes or USE_GCC=any,
 - with USES=fortran,
 - using Mk/bsd.octave.mk which in turn features USES=fortran, and
 - with USES=compiler specifying openmp, nestedfct, c11, c++0x, c++11-lang,
   c++11-lib, c++14-lang, c++17-lang, or gcc-c++11-lib
plus, everything INDEX-11 shows with a dependency on lang/gcc9 now.

PR:		238330

Bump PORTREVISION for ports depending on the canonical version of GCC
defined via Mk/bsd.default-versions.mk which has moved from GCC 7.4 t
GCC 8.2 under most circumstances.

This includes ports
 - with USE_GCC=yes or USE_GCC=any,
 - with USES=fortran,
 - using Mk/bsd.octave.mk which in turn features USES=fortran, and
 - with USES=compiler specifying openmp, nestedfct, c11, c++0x, c++11-lang,
   c++11-lib, c++14-lang, c++17-lang, or gcc-c++11-lib
plus, as a double check, everything INDEX-11 showed depending on lang/gcc7.

PR:		231590

devel/libevent2: drop historical suffix after r362796

PR:		216777
Approved by:	mm (maintainer)

devel/libevent2: update to 2.1.8 and cleanup

- DEFAULT_VERSIONS += ssl=openssl-devel is now supported
- devel/py-event and devel/p5-Event-Lib are marked BROKEN

Changes:	https://github.com/libevent/libevent/raw/release-2.1.8-stable/whatsnew-2.1.txt
Changes:	https://github.com/libevent/libevent/raw/release-2.1.8-stable/ChangeLog
PR:		216527
Exp-run by:	antoine
Approved by:	mm (maintainer)

- Update to 201606062304 development snapshot
- Reset PORTREVISION in slave ports to zero

PR:		210086
Submitted by:	myself
Approved by:	gahr, miwi (mentor, implicit)

- Unconditionally define PORTREVISION in subports
    to skip unneccessary bump slaves by master port touching
- Pass master's CONFIGURE_ARGS to slaves
- Option to select mail/opensmtpd[-devel] as build/run dependency
    (and corresponding libasr via this)
- Pass pkgconfig dependency only to subports which need it.
- Adjust dependencies in subports

Submitted by:	myself
Reviewed by:	adamw, gahr
Approved by:	adamw, gahr, miwi (mentor, implicit)
Sponsored by:	milk and cookies
Differential Revision:	https://reviews.freebsd.org/D6607

Split opensmtpd-extras into a bunch of slave ports. Right now -extras
only has the table stuff, but there are many more pieces. Having
the default package install postgresql, redis, and mysql when all you
wanted was passwd support, is overkill. Ports for filters will come
soon.

The -extras port retains its OPTIONS (and still installs everything
possible, so there's no disruption for current users).

Approved by:	gahr (maintainer)