title: HttpClient is not found in .NET 4.5
body: <p>I am trying to use the new <code>HttpClient</code> in .NET 4.5, but Visual Studio complains that it doesn't exist. I have <code>System.Net</code>, but when I type <code>System.Net.Http</code>, it complains for that too.</p>
  
  <p>Am I supposed to download a new distributable for this class?</p>