Avoid leaving stale sa-compile output lying around.

Closes: 913571

This is needed because we use dh_installinit --no-enable

This avoids the problem described in
https://lintian.debian.org/tags/maintainer-script-should-not-use-recursive-chown-or-chmod.html
and elsewhere.

job's execution. (Closes: 890650)

Was useful in development, but doesn't need to ship in a release.

The init script needs to handle the new name (spamd), and the upgrade process
needs to handle the transition. It accomplishes this by stopping the older
version of the daemon in preinst when upgrading from a package using the
previous scheme.

The ENABLED setting in /etc/default/spamassassin has been a pain for some time.
This pattern is explicitly deprecated by policy (section 9.3.3.1), so we'll
start transitioning away from it. For now, if runnning sysvinit and ENABLED is
set to 0 (or unset), then we will convert the rc?.d symlinks to K links.

A future revision, after the next stable release, will drop this migration
mechanism, at which point the transition will be complete.

ENABLED will still be supported, but won't be explicitly set in the default
/etc/default/spamassassin file. Sysvinit scripts will be installed as K links
by default. Systemd unit will be disabled. Docs updated to indicate that
update-rc.d is the recommended way to enable spamd.

binary-arch had a dependency on phony rules. Update it (recursively) to depend
on non-phony equivalents.

* Refresh several patches.

* Drop patches that are present in this upstream release.