Update to 1.41
    
    - New upstream release 1.41
      - Update to Devel::PPPort-3.56
      - csv2xls uses sheetname as csv2xlsx
      - csv2xlsx: support images (each image gets its own tab)
      - More docs (data validation)
      - It's 2020
      - No binary literals in fixed error messages
      - Fix auto_diag > 2 to die when headers are used (GH#19)