ndi.cloud.upload.zip_for_upload

  ZIP_FOR_UPLOAD - Create a zip file for uploading to the NDI cloud
    [B, MSG] = ndi.cloud.upload.ZIP_FOR_UPLOAD(D, DOC_FILE_STRUCT, TOTAL_SIZE, DATASET_ID)

  Inputs:
   D - the ndi.database object
   DOC_FILE_STRUCT - A structure with the following fields:
   'uid' - The uid of the file
   'name' - The name of the file
   'docid' - The document id that the file is associated with
   'bytes' - The size of the file in bytes
   'is_uploaded' - A flag indicating if the file is uploaded
   TOTAL_SIZE - The total size of the files to be uploaded
   DATASET_ID - The dataset id

  Outputs:
    B - did the upload work? 0 for no, 1 for yes
    MSG - An error message if the upload failed; otherwise ''