vis.revcorr.json_file_processor

  JSON_FILE_PROCESSOR - generate a list of useful data for reverse
  correlation from the json file.

  [S,KX_V, KY_V, FRAMETIMES, SPIKETIMES] = vis.revcorr.json_file_processor(FILENAME)

  Inputs:
   FILENAME - the directory of JSON file to be processed

  OUTPUTS:
   S - the sign for the reconstruction
   KX_V - the kx vector for the reconstruction
   KY_V - the ky vector for the reconstruction
   FRAMETIMES - the time point at which each frame appeared
   SPIKETIMES - the time that this cell spikes during the experiment