Truncate IDs to a more reasonable length

paste.go

@@ -45,7 +45,7 @@ func createPost(w http.ResponseWriter, r *http.Request) {
 	data := r.FormValue("stuff")
 	h := md5.New()
 	idHash := h.Sum([]byte(data))
-	id := base64.StdEncoding.EncodeToString(idHash)
+	id := base64.StdEncoding.EncodeToString(idHash)[:20]
 
 	err := ioutil.WriteFile(id+".txt", []byte(data), 0600)
 	if err != nil {