Move dh-kaboxer back to debian packaging

The upstream installation mechanism incorrectly renames the target
directories to all lowercase:
pypa/setuptools#2480

debian/kaboxer.install

@@ -0,0 +1,5 @@
+dh-kaboxer/Buildsystem/kaboxer.pm /usr/share/perl5/Debian/Debhelper/Buildsystem
+dh-kaboxer/Sequence/kaboxer.pm /usr/share/perl5/Debian/Debhelper/Sequence
+dh-kaboxer/dh_kaboxer /usr/bin
+dh-kaboxer/postinst-kaboxer /usr/share/debhelper/autoscripts
+dh-kaboxer/postrm-kaboxer /usr/share/debhelper/autoscripts

setup.cfg

@@ -29,9 +29,3 @@ share/man/man5 =
   kbxbuilder.apps.yaml.5
   kbxbuilder.config.yaml.5
 /etc/sudoers.d = sudoers.d/kaboxer
-bin = dh-kaboxer/dh_kaboxer
-share/perl5/Debian/Debhelper/Buildsystem = dh-kaboxer/Buildsystem/kaboxer.pm
-share/perl5/Debian/Debhelper/Sequence = dh-kaboxer/Sequence/kaboxer.pm
-share/debhelper/autoscripts =
-  dh-kaboxer/postinst-kaboxer
-  dh-kaboxer/postrm-kaboxer