csv header issue fixed, directory structure changed

- program now works with csv files without or incorrect headers
- directory structure redesigned; we do not need the files to be in
'dataset1', 'dataset2', 'dataset3' subdirectories any more. All the
ground truth csv files can be directly in <ground_truth_dir>, and all
the output csv files can be in <cps_output_dir>
- also appropriate prefix have been added to parameter csv files