autounionfs binary: add -version flag.

example/autounionfs/main.go

@@ -9,6 +9,7 @@ import (
 )
 
 func main() {
+	version := flag.Bool("version", false, "print version number")
 	debug := flag.Bool("debug", false, "debug on")
 	threaded := flag.Bool("threaded", true, "threading on")
 	delcache_ttl := flag.Float64("deletion_cache_ttl", 5.0, "Deletion cache TTL in seconds.")
@@ -17,6 +18,11 @@ func main() {
 		"deletion_dirname", "GOUNIONFS_DELETIONS", "Directory name to use for deletions.")
 	flag.Parse()
 
+	if *version {
+		fmt.Println(fuse.Version())
+		os.Exit(0)
+	}
+
 	if len(flag.Args()) < 2 {
 		fmt.Println("Usage:\n  main MOUNTPOINT BASEDIR")
 		os.Exit(2)