Add empty functions in storage.js for API
Add empty functions in storage.js for API

[1] getList(folderD, callback)
[2] loadFile(fileID)
[3] saveFile(fileID,file)
[4] createFile()
[5] deleteFile(fileID)
[6] createFolder()
[7] deleteFolder(folderID)

nus-mtp/sashimi-note,nus-mtp/sashimi-note,nus-mtp/sashimi-note