web.config is different in MVC3 and MVC4 - asp.net-mvc-3

Question

Im doing a web application in C# and ASP.NET MVC4.
On inspection of the web.config file I noticed that MVC4 has this:
<system.web>
<compilation debug="true" targetFramework="4.0" />
whereas if you look in the MVC3 web.config file you will see the following:
<system.web>
<compilation debug="true" targetFramework="4.0">
<assemblies>
<add assembly="System.Web.Abstractions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<add assembly="System.Web.Helpers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<add assembly="System.Web.Routing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<add assembly="System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<add assembly="System.Web.WebPages, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
</assemblies>
</compilation>
So, my question is why are the assemblies not in MVC4 web.config? Or are they elsewhere?
Many thanks.

Answer 1

Most of this is now all "rolled up"
namespaces are what you typically will now see
If you need to add in an Assembly you are free to do so.
http://www.asp.net/whitepapers/mvc4-release-notes
You should still be able to do this:
<compilation debug="true" targetFramework="4.5">
<assemblies>
<add assembly="System.Data.Entity, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
</assemblies>
</compilation>

Answer 2

if you scroll a bit you'll see the both web.config have the namespaces added in them, I guess that would do.
<pages>
<namespaces>
<add namespace="System.Web.Helpers" />
<add namespace="System.Web.Mvc" />
<add namespace="System.Web.Mvc.Ajax" />
<add namespace="System.Web.Mvc.Html" />
<add namespace="System.Web.Routing" />
<add namespace="System.Web.WebPages" />
</namespaces>
</pages>