title: Add-Migration command fails with "type is not resolved"(where "type" is inner entity framework class)
body: <p>I have already used an entity framework with separate migration package(for 3.5 or 4.0, don't remember), and with included migrations api(4.3, 5.0).</p>
  
  <p>But today i have created a new project(empty MVC4.0 project), install latest stable EF(4.3) and recieve error below on the "pm > Add-Migration initital" command</p>
  
  <pre><code>System.Runtime.Serialization.SerializationException: Type is not resolved for member 'System.Data.Entity.Migrations.Design.ToolingFacade+GetPendingMigrationsRunner,EntityFramework    , Version=4.3.1.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.
     at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
     at System.Data.Entity.Migrations.Design.ToolingFacade.Run(BaseRunner runner)
     at System.Data.Entity.Migrations.Design.ToolingFacade.GetPendingMigrations()
     at System.Data.Entity.Migrations.AddMigrationCommand.&lt;&gt;c__DisplayClass2.&lt;.ctor&gt;b__0()
     at System.Data.Entity.Migrations.MigrationsDomainCommand.Execute(Action command)
  </code></pre>
  
  <p>Then i am trying to switch to EF5.0 and an error still here, with one difference in a version:</p>
  
  <pre><code>System.Runtime.Serialization.SerializationException: Type is not resolved for member 'System.Data.Entity.Migrations.Design.ToolingFacade+GetPendingMigrationsRunner,EntityFramework      , Version=4.4.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.
  </code></pre>
  
  <p>It is first time when i recieve this error. The<br>
      "System.Data.Entity.Migrations.Design.ToolingFacade" class exists and the "GetPendingMigrationsRunner " subclass in it also exists in a referenced EntityFramework assembly.</p>
  
  <p>Anyone knows what may cause an error? Migrations works ok for another project on MVC4.0, on those i have choosen standart(not empty) project template.</p>
  
  <p>Thanks!</p>