bump debian standards version
prebuilt shenanigans allow removal of build dependency on self
rm debian/README.Debian, which merely listed the upstream URL
update man page oaklisp(1)
longer long doc decriptions, and no initial article
bump to dh 9
update debian/rules

Use dpkg-buildpackage in debian/rules, and pass explicitly.

Remove dh_targets stuff, which is brittle and only papers over the
least of the underlying debhelper sins.

Remove -O3 and the default -O2 seems sufficient.