Integrate release procedure in Makefile

Makefile

@@ -7,10 +7,17 @@ all: nethogs decpcap_test test
 	$(MAKE) -C src -f MakeApp.mk $@
 	$(MAKE) -C src -f MakeLib.mk $@
 
-.PHONY: tgz
+.PHONY: tgz release
 tgz: clean
 	git archive --prefix="nethogs-$(VERSION)/" -o "../nethogs-$(VERSION).tar.gz" HEAD
 
+release: clean
+	git tag -s v$(RELEASE) -m "Release $(RELEASE)"
+	git archive --prefix="nethogs-$(RELEASE)/" -o "../nethogs-$(RELEASE).tar.gz" "v$(RELEASE)"
+	gpg --armor --detach-sign "../nethogs-$(RELEASE).tar.gz"
+	git push --tags
+	echo "now upload the detached signature to https://github.com/raboof/nethogs/releases/edit/v$VERSION"
+
 check:
 	$(MAKE) -C src -f MakeApp.mk $@