title: Msbuild get OutputPath from main project
body: <p>Say I have a <code>game.exe</code> that depends on <code>engine.dll</code>. When I build the <code>game.csproj</code> I want the <code>engine.csproj</code> to copy some stuff to the OutputPath of the project that is referencing it. 
  So in this example case, I want <code>engine.csproj</code> to copy something to the <strong>OutputPath</strong> of <code>game.csproj</code></p>
  
  <p>How do I get the $(OutputPath) of <code>game.csproj</code> in <code>engine.csproj</code>?</p>
  
  <p>The reason I want to do this is because I'm building a content project in game and engine like this:</p>
  
  <pre><code>&lt;Target Name="BuildContent"&gt;
      &lt;MSBuild Projects="Content\Content.contentproj" 
               Properties="OutputPath=MAINPROJECTPATH" /&gt;
  &lt;/Target&gt;
  </code></pre>
  
  <p>So I need to specify the <strong>OutputPath</strong> to the 'main project' which is the game.</p>