public ActionResult CreateFile(int dirId)
        {
            var viewModel = new SourceFileViewModel
            {
                SourceFile = new SourceFile(),
                ParentDirId = dirId
            };

            return View("EditFile", viewModel);
        }
        public ActionResult EditFile(int dirId, int fileId)
        {
            var directory = ProjectRepository.Project.SourceDirs.Directories.Single(sd => sd.DirId == dirId);

            var file = directory.Files.Single(sf => sf.FileId == fileId);

            var viewModel = new SourceFileViewModel
            {
                SourceFile = file,
                ParentDirId = dirId
            };

            return View(viewModel);
        }