PERIODIC CHECKS (tidy, pylint etc)

Every few months:

• clang-tidy
• pylint
• test coverage
• no move c'tors exposed to Python

Run clang-tidy in a special build directory called tidy/:

cmake .. -DBORNAGAIN_PYTHON=OFF -DBA_TIDY=ON
make

Run pylint from top-level source directory

pylint <all python sources>

As new checks are added to these tools, we need to update .clang-tidy and .pylintrc accordingly, disabling checks that are not helpful for us.