Cleanly close the HID interface when restarting

hardware/blink/77-blink1.js

@@ -50,6 +50,11 @@ function Blink1Node(n) {
                 node.warn("No Blink1 found");
             }
         });
+        this.on("close", function() {
+            if (blink1 && typeof blink1.close == "function") {
+                blink1.close();
+            }
+        });
         var blink1 = new Blink1.Blink1();
     }
     catch(e) {