Install additional auxiliary script (and accompanying documentation).
Fix pkgdesc of split packages.

Replace libnsl with libnsl.so in depends for postfix.

Add -DUSE_LDAP_SASL to build flags, so that LDAP SASL bind support is added:
https://bugs.archlinux.org/task/69871

Introduce split packages postfix-{cdb,ldap,lmdb,mysql,pcre,pgsql,sqlite},
which allows for a slimmer installation, while not pulling in
all available database backends, if they are not required.
Add upstream PGP key 622C7C012254C186677469C50C0B590E80CA15A7 to
validpgpkeys (Wietse Venema <wietse@porcupine.org>).
Add HAS_LMDB to CFLAGS to actually build the lmdb feature.
Add split packages to postfix' optdepends.
Add .install file for postfix notifying the users about the change in
packaging.
Remove obsolete postfix-tools from conflicts/provides/replaces.
Remove unreproducible makedefs file also from postfix-files.
Introduce drop-in files for dynamicmaps.cf and postfix-files for
each of the split packages.

The previous version was missing a tmpfiles.d setup for /var/spool/postfix/hold (FS#68658).

Switch to correct license (EPL).
Add a patch to set defaults in main.cf in prepare().
Split AUXLIBS into the various specific subcomponents.
Provide SHLIB_RPATH to achieve full RELRO.
Add dynamicmaps=yes so that dynamic libraries are split.
Add CPPFLAGS to OPT, so that fortify is applied.
Replace call to custom post-install script with tmpfiles.d.
Remove unneeded patch and customizations.
Apply mild hardening to the systemd service.
Add tmpfiles.d integration for sgid binaries and custom chmod
directories in /var/spool.
Update maintainer info.