Add make release target for simplified maintenance

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Makefile.am

@@ -3,3 +3,36 @@ pkgconfig_DATA  = libeditline.pc
 doc_DATA        = README LICENSE CHANGELOG
 EXTRA_DIST      = LICENSE CHANGELOG INSTALL
 SUBDIRS         = src include man examples
+
+## Generate MD5 checksum file
+MD5 = md5sum
+md5-dist:
+	@for file in $(DIST_ARCHIVES); do	\
+		$(MD5) $$file > $$file.md5;	\
+	done
+
+## Check if tagged in git
+release-hook:
+	if [ ! `git tag | grep $(PACKAGE_VERSION)` ]; then				\
+		echo;									\
+		printf "\e[1m\e[41mCannot find release tag $(PACKAGE_VERSION)\e[0m\n";	\
+		printf "\e[1m\e[5mDo release anyway?\e[0m "; read yorn;			\
+		if [ "$$yorn" != "y" -a "$$yorn" != "Y" ]; then				\
+			printf "OK, aborting release.\n";				\
+			exit 1;								\
+		fi;									\
+		echo;									\
+	else										\
+		echo;									\
+		printf "\e[1m\e[42mFound GIT release tag $(PACKAGE_VERSION)\e[0m\n";	\
+		printf "\e[1m\e[44m>>Remember to push tags!\e[0m\n";			\
+		echo;									\
+	fi
+
+## Target to run when building a release
+release: dist release-hook md5-dist
+	@for file in $(DIST_ARCHIVES); do						\
+		printf "$$file    \tDistribution tarball\n";				\
+		printf "$$file.md5\t"; cat $$file.md5 | cut -f1 -d' ';			\
+		mv $$file* ../;								\
+	done