wip/py-cppimport 20.8.4.2 NetBSD

TODO: Adjust the following lines from README.md

##### If you've used cppimport version 0.0.\*, some new features for you! Compiler arguments, multiple source files, bug fixes! Read on.

# Import C or C++ files directly from Python! Let's try it out. First, if you're on Linux or OS X, install with the terminal command `pip install cppimport`.

Most cppimport users combine it with [pybind11](https://github.com/pybind/pybind11), but you can use a range of methods to create your Python extensions. Raw C extensions, Boost.Python, SWIG all work. Let's look at a simple C++ extension:

```c++ #include <pybind11/pybind11.h>

namespace py = pybind11;

int square(int x) { return x * x; }

PYBIND11_MODULE(somecode, m) { m.def("square", &square); } ...