Propogate additional compilation data from RoslynCompilationService

* Update CompilationFailedException to include path of file being compiled
* Pass in path being compiled to Rolsyn.
* Adding doc comments for compilation pieces

Fixes #869
We do have strings like this all over the place so I'd rather keep it consistent. 

Git shouldn't cause issues because it would checkout with \n on non-Windows machines and Env.NewLine would be the \n.