Using commented header line (flat file readers)
Currently, it is not possible to both ignore comments and use a commented header when reading a CSV file. From the documentation for the `header` argument of [`read_table`](https://pandas.pydata.org/pandas-docs/stable/generated/pandas.read_table.html) etc.:

> Note that this parameter ignores commented lines and empty lines if `skip_blank_lines=True`, so `header=0` denotes the first line of data rather than the first line of the file.

It would be great if one could specify that `header` should **not** skip commented lines so that a header can be used even if it happens to contain the comment character.

Other people requesting this:
- https://stackoverflow.com/q/30311776
- https://github.com/pandas-dev/pandas/issues/8727#issuecomment-262167338