Add CMakelists and fix warnings

[dalboris]

Hi @memononen ,

I know that you're not maintaining this library anymore. Still, I'm currently using it in https://github.com/vgc/vgc, and I've made very small changes:

• Adding a CMakeLists.txt file
• Fixing a compiler warning

See: master...vgc:vgc-mods

Would it make sense if I submit pull requests with the above changes, and then if you bump the version to 1.0.3? Note that before doing the PRs, I would improve the CMakeLists.txt a little: I'm currently printing a message which was okay in my use case, but is most likely undesirable for other clients.

One other option might be that I become the official maintainer, if that sounds like something you'd be interested in.

Thanks for this great library,

Boris