Thank you for open-sourcing SD/Fast

[esba1ley]

@sherm1, thank you for making SD/Fast Open Source! I have made a few mods that make it compile and work under MacOS. Can I push the feature branch here so we can collaborate and make sure I didn't miss anything? I got the four-bar example to match the documentation, running completely on MacOS and using the clang/llvm compiler.

[sherm1]

Thanks -- yes, that would be great. I don't have a Mac so can't test it myself but I can run your changes on Ubuntu and Windows to make sure nothing broke. Please feel free to submit a PR with your changes and I'll review.

[esba1ley]

See #20.