cat_csv: Ignore any duplicated headers instead of requiring each CSV to have a header identical to the first. Rewrote to pass the CSVs through as lines rather than parsing each row. Because the CSVs are not parsed, checked that all CSVs have the same dialect.
cat_csv: Ignore any duplicated headers instead of requiring each CSV to have a header identical to the first. Rewrote to pass the CSVs through as lines rather than parsing each row. Because the CSVs are not parsed, checked that all CSVs have the same dialect.