Debian: Clean up /etc/rsbackup on purge

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=773181

Makefile.am

@@ -18,6 +18,7 @@ EXTRA_DIST=scripts/txt2src scripts/htmlman scripts/dist \
 	debian/changelog debian/control debian/copyright \
 	debian/doc.rsbackup \
 	debian/rsbackup.conffiles debian/rsbackup.postinst debian/rules \
+	debian/rsbackup.postrm \
 	README.md
 
 echo-distdir:

debian/rsbackup.postrm

@@ -0,0 +1,22 @@
+#! /bin/sh
+# Copyright © 2014 Richard Kettlewell.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+set -e
+case "$1" in
+purge )
+  rm -f /etc/rsbackup/local
+  rmdir --ignore-fail-on-non-empty /etc/rsbackup
+  ;;
+esac

debian/rules

@@ -48,6 +48,7 @@ binary-${PACKAGE}: build
 	mkdir -p debian/${PACKAGE}/usr/share/doc-base
 	cp debian/${PACKAGE}.conffiles debian/${PACKAGE}/DEBIAN/conffiles
 	cp debian/${PACKAGE}.postinst debian/${PACKAGE}/DEBIAN/postinst
+	cp debian/${PACKAGE}.postrm debian/${PACKAGE}/DEBIAN/postrm
 	cp tools/rsbackup.hourly debian/${PACKAGE}/etc/cron.hourly/rsbackup
 	cp tools/rsbackup.daily debian/${PACKAGE}/etc/cron.daily/rsbackup
 	cp tools/rsbackup.weekly debian/${PACKAGE}/etc/cron.weekly/rsbackup