Add system-cli and an user-merging tool

cmd/system-cli/flags.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	_ "github.com/joho/godotenv/autoload"
+	"github.com/namsral/flag"
+)
+
+func flags(prefix string, mountFlags ...func(...string)) {
+	for _, mount := range mountFlags {
+		mount(prefix)
+	}
+	flag.Parse()
+}