Asp.Net MVC3 to MVC4 Upgrade Tool?

问题

I'm aware of manual guides to upgrade from 3 to 4 like this one: http://www.dotnetexpertguide.com/2011/12/upgrade-aspnet-mvc-3-project-to-mvc-4.html

The guides vary in their details which clearly signals danger. Is there a tool that handles the transition from an MVC3 project to MVC4? This would implicitly mean migrating from .Net 4 to .Net 4.5, which does have some significant implications in terms of all the namespace redirects Microsoft added between the 2 versions.

I'm also aware of manual guides that basically say to give up on upgrading and instead just create a new project and port things over piece by piece into the new project. This has a lot of obvious opportunities for small mistakes to create big problems.

So, a tool that's been tested I can count on to not make a silly mistake like I might would really help here. Does that exist? There's a tool to get from MVC2 to 3, so not finding one for 3 to 4 surprised me.

Background for why I'd like to upgrade: we have several newer projects on .Net 4.5 MVC4, and an important older project on .Net 4 MVC3 (with some .Net 2 and MVC 2 mixed in...), and the more our shared libraries move forward the more that old project struggles. We can freeze the last working on the shared libraries obviously, or fork them and maintain 2 versions... obviously neither of these is very appealing. I'd prefer to just update the toolset on the older project and bring everything into parity.