CSVFileReader is a specialisation of TextFileReader, that allow reading
a CSV line field by field.
TextFileReader:
- Make private attributes protected to allow derivation.
- Add attribute current_line_nb.
- Add function read_nonblank_line().
- Delete useless accessor get_name().
Update InputCSV to use CSVFileReader.
Adapt unit tests for InputCSV and InputLogCSV: EOF is not reached right
after reading the last line, but after trying (and failing) to read one
more line.