* add console.log
* modify file name from json to js
* only parse doc attribute
* use file stream
* fs, JSONStream.parse doc
* use on event
* modify code format
+ add new file Backup/data-2.json
* add recurse func
* try JSONStream.stringify
* try JSONStream.stringify ...
* use JSONStream.stringify
* stringify.write some msgs
* make good use of stringify
* update stringify
* use stringifyObject