Add Firefox make goal (#41)

Makefile

@@ -1,31 +1,48 @@
-CLEAN_FILES := chrome
+CLEAN_FILES := chromium firefox
 
 .PHONY: all
-all: extension chrome
+all: extension chromium firefox
 
 .PHONY: extension
 extension:
 	$(MAKE) -C src
 
-CHROME_FILES := manifest.json \
-				*.css \
-				*.png \
-				popup/*.html \
-				popup/*.svg \
-				options/*.html
-CHROME_FILES := $(wildcard $(addprefix src/,$(CHROME_FILES))) \
-				src/css/popup.dist.css \
-				src/css/options.dist.css \
-				src/js/background.dist.js \
-				src/js/popup.dist.js \
-				src/js/options.dist.js \
-				src/js/inject.dist.js
-CHROME_FILES := $(patsubst src/%,chrome/%,$(CHROME_FILES))
+EXTENSION_FILES := \
+	src/*.css \
+	src/*.png \
+	src/popup/*.html \
+	src/popup/*.svg \
+	src/options/*.html
+EXTENSION_FILES := \
+    $(wildcard $(EXTENSION_FILES)) \
+	src/css/popup.dist.css \
+	src/css/options.dist.css \
+	src/js/background.dist.js \
+	src/js/popup.dist.js \
+	src/js/options.dist.js \
+	src/js/inject.dist.js
+CHROMIUM_FILES := $(patsubst src/%,chromium/%, $(EXTENSION_FILES))
+FIREFOX_FILES  := $(patsubst src/%,firefox/%,  $(EXTENSION_FILES))
 
-.PHONY: chrome
-chrome: extension $(CHROME_FILES)
+.PHONY: chromium
+chromium: extension $(CHROMIUM_FILES) chromium/manifest.json
 
-$(CHROME_FILES) : chrome/% : src/%
+$(CHROMIUM_FILES) : chromium/% : src/%
+	[ -d $(dir $@) ] || mkdir -p $(dir $@)
+	cp $< $@
+
+chromium/manifest.json : src/manifest-chromium.json
+	[ -d $(dir $@) ] || mkdir -p $(dir $@)
+	cp $< $@
+
+.PHONY: firefox
+firefox: extension $(FIREFOX_FILES) firefox/manifest.json
+
+$(FIREFOX_FILES) : firefox/% : src/%
+	[ -d $(dir $@) ] || mkdir -p $(dir $@)
+	cp $< $@
+
+firefox/manifest.json : src/manifest-firefox.json
 	[ -d $(dir $@) ] || mkdir -p $(dir $@)
 	cp $< $@