s3-smbd: Support systemd 230

s3-smbd: Support systemd 230

systemd 230 version finally deprecated libsystemd-daemon/libsystemd-journal split
and put everything in libsystemd library.

Make sure HAVE_LIBSYSTEMD define is supported in the code (we already
have it defined by the waf).

Patch is based on the code proposed by Zbigniew Jędrzejewski-Szmek
from systemd project.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11936

Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Reviewed-by: Alexander Bokovoy <ab@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
Autobuild-User(master): Andreas Schneider <asn@cryptomilk.org>
Autobuild-Date(master): Wed May 25 20:25:44 CEST 2016 on sn-devel-144