Platform independent build system

[christianrauch]

Would you mind to add CMake (or alternative platform independent) build scripts?
At the moment, the build procedure is limited to the Apple ecosystem. OpenCL is deprecated in macOS. The Xcode project files might become redundant at some point.

[rsnemmen]

sure. Contributions are welcome to add CMake build scripts. I don't have the time to do this myself, but any pull requests will be welcome.