cpplint.py is outdated

[bt2901]

There is a utils/cpplint.py file. As far as I understand, this is a modified version of google code style linter (with one additional check added: see #178).

The problem is, this version is really outdated. It silently crashes when run with Python 3. Nowadays, cpplint is available on PyPi, so the best way appears to change codestyle.sh to run this more recent version:

instead of

  3 cat utils/cpplint_files.txt | xargs python utils/cpplint.py --linelength=120 || exit 1

run this

  3 cat utils/cpplint_files.txt | xargs python -m cpplint --linelength=120 || exit 1

The problem is, we'll lose additional check from #178 because you cannot pass extra_check_functions into cpplint (they are hardcoded). The best solution seems to make a fork of Google cpplint repo, tweak some stuff inside it and then install the fork via pip.

I'm disabling codestyle_checks.sh for now.

PS: does cpplint check for BigARTM-specific code style rules from https://github.com/bigartm/bigartm/blob/master/docs/devguide/code_style.txt ? Notably, the two spaces thing? I don't think it does.

PPS: Also, it reports 57 total errors currently. These probably should be fixed.