Add support for absolute paths

In reference to https://github.com/nwg-piotr/nwg-bar/issues/1

Makefile

@@ -8,7 +8,7 @@ get:
 	go get "github.com/sirupsen/logrus"
 
 build:
-	go build -o bin/nwg-drawer *.go
+	go build -o bin/nwg-drawer .
 
 install:
 	mkdir -p /usr/share/nwg-drawer
@@ -21,5 +21,5 @@ uninstall:
 	rm /usr/bin/nwg-drawer
 
 run:
-	go build -o bin/nwg-drawer *.go
+	go build -o bin/nwg-drawer .
 	bin/nwg-drawer

main.go

@@ -190,7 +190,9 @@ func main() {
 	}
 	log.Info(fmt.Sprintf("Found %v pinned items", len(pinned)))
 
-	cssFile := filepath.Join(configDirectory, *cssFileName)
+	if !strings.HasPrefix(*cssFileName, "/") {
+		*cssFileName = filepath.Join(configDirectory, *cssFileName)
+	}
 
 	appDirs = getAppDirs()
 
@@ -216,12 +218,12 @@ func main() {
 
 	cssProvider, _ := gtk.CssProviderNew()
 
-	err = cssProvider.LoadFromPath(cssFile)
+	err = cssProvider.LoadFromPath(*cssFileName)
 	if err != nil {
-		log.Errorf("ERROR: %s css file not found or erroneous. Using GTK styling.", cssFile)
+		log.Errorf("ERROR: %s css file not found or erroneous. Using GTK styling.", *cssFileName)
 		log.Errorf("%s", err)
 	} else {
-		log.Info(fmt.Sprintf("Using style from %s", cssFile))
+		log.Info(fmt.Sprintf("Using style from %s", *cssFileName))
 		screen, _ := gdk.ScreenGetDefault()
 		gtk.AddProviderForScreen(screen, cssProvider, gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)
 	}