BUG: ViewComponents model inconsistency with MVC Views.

[Bartmax]

Based usage setting the model to ViewData.Model property on a ViewComponent result in the model being null on the view:

// NRE when invoking Default.cshtml

ViewData.Model = new SomeModel();
return View();

// works ok!

var model = new SomeModel();
return View(model);

[NTaylorMullen]

7036e2b