title: Pass property value from TFS Build Definition to proj file
body: <p>I have a build definition set up in my TFS 2012 instance.  In this Build Definition I want to pass in a custom argument and access said argument in my .csproj file.  For example:</p>
  
  <pre><code>MSBuild Arguments: /p:MyFoo=1
  </code></pre>
  
  <p>In my .csproj file I want to do this:</p>
  
  <pre><code>&lt;ItemGroup Condition=" '$(MyFoo)' == '1' "&gt;
  </code></pre>
  
  <p>Is this possible, or am I going about this incorrectly?</p>