Prototype of v2 of Blade.

Replaces RazorEngine with directly calling MVC4 APIs. It's much simpler and cleaner than the previous Razor implementation. It also provides USEFUL errors with source context if there's a syntax error or runtime error in a Razor file (!!!!).

This does introduce some breaking changes. You must add '.cshtml' on the end of view paths now, but relative paths work fine still. The BladeHtmlHelper is gone, replaced by the normal MVC HtmlHelper - note that some pieces of it may behave oddly as there is no model binding or anything.
Blade Postback & Model Binding Support

This commit adds postback (and XHR) support to Blade, enabling presenters to handle postback in a clean fashion by using ASP.NET MVC Model Binding to bind posted values to your viewmodel automatically.

MVC model validation attributes and validation controls are fully supported for Razor views, as are MVC HTML helpers (@Html.TextBoxFor(x=>x.StringField), for example). User Controls and Web Controls support validation, but they do not have ModelState to pass it around to so you'd need to manually parse the validation result in the presenter for those.

To support postback, if using a SitecorePresenter or SynthesisPresenter, simply override the HandlePostBackWithModelBinding method. The method is invoked if HTTP POST is requested, and model binding is automatically executed. Similar methods exist for XHR and non-automatic-modelbinding for both.

The postback handling occurs immediately after the OnLoad event just like web forms usually does for submit event handlers.
Code review and comment updates; Blade 2 RC1
Fixed up nuspec and assembly version
Support for @model in views - you no longer need to use @inherits RazorRendering<Tmodel>
Switch to using XDT for NuGet install transform to get more precise transform control for new and upgrade installs
Fix error if model type 'object' was requested
Fix null ref error if model type is object
Switch VS template to use @model
Allow overriding the data source of a SitecorePresenter, if for some reason you felt the need to test with Items instead of Synthesis
R#ing