Added a target to create a zip file with the distribution.

It's more friendly with Windows users.

Author: jaragunde

Makefile

@@ -3,3 +3,6 @@ VERSION=2.0~beta1
 tgz:
 	tar zcf phpreport_$(VERSION).tar.gz --exclude=Makefile --exclude=*~ \
 		--exclude=config/config.php --exclude=phpreport_$(VERSION).tar.gz *
+
+zip: tgz
+	tar tf phpreport_$(VERSION).tar.gz | zip -@ phpreport_$(VERSION).zip