…tion

Split lines before comparing captured output against expected output. On
Microsoft Windows, the CSV output will use "\r\n" as line separator,
which is different than the "\n" stored in the files containing the
expected output. By using `.splitlines()` the platform-dependent line
separators are removed and the content can be compared for equality
independently of in which platform was produced.

Improve the hidden fields functionality by passing the list of hidden
fields in the constructor instead of requiring a separate method for
that effect.

Add support for showing totals for certain fields to the PrettyTable
class and update codebase to use the new feature.