Split source files and header files

[mattangus]

trafficstars

I'm currently playing with the idea of packing this up with conan for easy accessibility. At first attempt it requires workarounds for dealing with the header files.

Would you be open to a PR that splits the header files into an include directory so that it's easier to consume downstream?

[pthom]

Hello,

I'm always open to interesting contributions, and your previous one was excellent, so please go ahead!