Add Visual Studio IDE support

[FiniteReality]

Closes #6

I have no idea if this builds on Linux. Probably not. Either way, I'll use this PR to track Visual Studio support.

C++ Projects

• [x] Loading C++ projects
• [x] Compiling C++ projects
• [ ] Running C++ projects

C Projects

• [ ] Loading C Projects
• [ ] Compiling C Projects
• [ ] Running C Projects

General

• [ ] Project-to-project references
• [ ] Package references
• [ ] Full IDE support (intellisense, etc.)
  • [x] Initial IDE support (Visual Studio picks up #included files and shows primitive intellisense, probably because it's smart)
  • [ ] Debugging (I have no idea what interfaces I need for this...)
  • [ ] Pack support (see #2)
  • [ ] Getting rid of that weird issue where Visual Studio tries to add a project GUID to the file. I don't know how the .NET SDK/project-system works around this, there's something non-obvious I'm missing.
• [ ] 0-100 Installation from VSIX