Commented Unassigned: ExcelCsvReader - CSV reader implementation [13097]

This is my contrib to the Library:

a CSV data reader implementation to extend ExcelReaderFactory.
Comments: ** Comment from web user: wizardgsz **

Bugfix in TokenizeLine, last "empty" token:

```
// ...
if (line.Trim().EndsWith(";"))
tokens.Add(token);
else if (!String.IsNullOrEmpty(token))
tokens.Add(token);

return tokens.ToArray();
```