CMake and pkgconfig support about inih

[benhoyt]

Hi @otavio, thanks for that. I'm uncertain about including make/build stuff in such a tiny project. But I don't know much about CMake or pkgconfig, so I'm open to hearing more or seeing your PR.

[otavio]

It is a widely used build system and it integrates way with cross-building environments. We did change the library to build static libraries for C and C++ and the pkgconfig allows for easy integration on existing projects.

A snapshot of what we use is here: https://github.com/OSSystems/inih

I need to rework this code and prepare a PR if you think this is worth.

[benhoyt]

Hi @otavio: I think I'd rather not include these. Not because they're not useful or a bad idea, but because then I'd have to maintain files/systems I know nothing about, and I don't have much bandwidth for inih at this point. Sorry!