Sbt modules

[davesmith00000]

This doesn't quite work yet, probably due to my lack of Scala Native knowledge. 😅

Check each commit in turn so you can see what I've done - sorry I've run out of time for now!

I think there's two things that may need to happen to make this work:

1. Definitely I'm not including your linking commands anywhere yet, i.e.:
   --native-compile -IC:\libs\SDL2\include --native-compile -IC:\libs\STB\include --native-compile -IC:\libs\glew\include --native-linking -lSDL2 --native-linking -LC:\libs\SDL2\lib --native-linking -LC:\libs\STB --native-linking -lstb_image --native-linking -LC:\libs\glew\lib\Release\x64 --native-linking -lglew32 --native-linking -lopengl32 --native-linking -lglu32

2. We might need to use something like sbt-crossproject to get the module linking right.

Maybe just use this PR as a starting point / for ideas?

[FinochioM]

Taking some time to fix other things before I check this PR, I did not forget about it tho, I promise!