Adds modelbuilder ui intergration

As we load the doctype editor, we detect if the install has the models
builder dlls, if not found / error, we should the normal save button,
otherwise you get a button + generate models option.
web.configs + translated prepared as well, but nothing is active untill
the zbu dlls are dropped in bin

src/Umbraco.Web.UI/Views/Web.config

@@ -22,6 +22,8 @@
         <add namespace="Umbraco.Web.Mvc" />
         <add namespace="umbraco" />
         <add namespace="Examine" />
+        <add namespace="Umbraco.Web.PublishedContentModels"/>
+        
       </namespaces>
     </pages>
   </system.web.webPages.razor>