The solution explorer should mirror the file system

One thing I and all other developers I've ever talked about it with **hate**, is the mismatch between what you see in the Solution Explorer of Visual Studio and the file system. Having to create a duplicate folder hierarchy for stuff that isn't within a project (files like `README.md` on the solution root, for instance) suck.

I think this is somewhat related to #106 and #197, but I believe it's important to express that most developers I know, including me, would like the Solution Explorer to be a physical file browser with a `.gitignore` applied and not a virtual explorer of incomprehensible stuff within the `.sln` file that is impossible to hand edit or make sense of.