Instead of finishing exception handling I figured out how to find `devenv.exe` and pipe its `/Build` output into Emacs 😎

It's slow to start up. A "handmade" build.bat would be faster, but I much prefer using GENie

I've done similar things before, but now I'm slowly parameterizing bits of it to be relatively easy to setup for future projects instead of cobbling a half-working form of it together each time.