Add $native.beep

I could have created an npm for this. I also could wash my hands every 10 seconds, but I'm not crazy, so I did neither.

native/v8_extensions/native.mm

@@ -25,7 +25,7 @@ namespace v8_extensions {
       "writeToPasteboard", "readFromPasteboard", "quit", "watchPath",
       "unwatchPath", "getWatchedPaths", "unwatchAllPaths", "moveToTrash",
       "reload", "setWindowState", "getWindowState", "isMisspelled",
-      "getCorrectionsForMisspelling"
+      "getCorrectionsForMisspelling", "beep"
     };
 
     CefRefPtr<CefV8Value> nativeObject = CefV8Value::CreateObject(NULL);
@@ -191,6 +191,10 @@ namespace v8_extensions {
       return true;
     }
 
+    else if (name == "beep") {
+      NSBeep();
+    }
+
     return false;
   }
   };