Makefile: Implement chrome target, and extract the version number.

Makefile

@@ -1,17 +1,21 @@
 BUILDDIR := build/
 NAME     := ipvfoo
+VERSION  := $(shell cat src/manifest.json | \
+              sed -n 's/^ *"version": *"\([0-9.]\+\)".*/\1/p' | \
+              head -n1)
 
 all: prepare firefox chrome
 
 prepare:
 	mkdir -p build
 
 firefox: prepare
-	rm -f ${BUILDDIR}${NAME}.xpi
-	cd src && zip -9r ../${BUILDDIR}${NAME}.xpi *
+	rm -f ${BUILDDIR}${NAME}-${VERSION}.xpi
+	cd src && zip -9r ../${BUILDDIR}${NAME}-${VERSION}.xpi *
 
 chrome:
-	echo "Chrome build not implemented, package manually"
+	rm -f ${BUILDDIR}${NAME}-${VERSION}.zip
+	zip -9r ${BUILDDIR}${NAME}-${VERSION}.zip src
 
 clean:
 	rm -rf ${BUILDDIR}