title: Use autofac in multiple project solution
body: <p>I have large wpf application. I simplify my problem with autofac. Let say I have ViewModelLocator where I create contrainer. ViewModelLocator is in Company.WPF project, this project refers Company.ViewModels project.  </p>
  
  <pre><code>var builder = new ContainerBuilder();
  builder.RegisterType&lt;MainWindowViewModel&gt;().AsSelf().SingleInstance();
  container = builder.Build();
  </code></pre>
  
  <p>Problem: MainWindowViewModel needs ICompanyService (I use CI) which is in Company.Services project, this project should not be reference from Company.WPF. ICompanyService is public and in same project (Company.Services) is also implementation CompanyService, but it is only internal. </p>
  
  <p>How can I setup Autofac for these? I normally use castel Wisndor, there are installers for these situation, is similar option in Autofac too?</p>