title: VS2015 shows a project as ignored
body: <p>I was wondering if anyone else has seen this problem I am having. The VS 2015 GUI shows all of the projects in my solution with a little red circle next to it. If I move the cursor over the project the tool tip says ignored. </p>
  
  <p><a href="https://i.stack.imgur.com/hzGx4.png" rel="noreferrer"><img src="https://i.stack.imgur.com/hzGx4.png" alt="Ignored Project"></a></p>
  
  <p>I haven't been able to find anything in the help on what it means. Any ideas?</p>
  
  <p>It doesn't seem to cause any problems, everything still compiles, just disconcerting.</p>
  
  <p>It's not explained here either:
   <a href="https://msdn.microsoft.com/en-us/library/y47ychfe(v=vs.140).aspx" rel="noreferrer">https://msdn.microsoft.com/en-us/library/y47ychfe(v=vs.140).aspx</a></p>
  
  <p>Environment:
   - VS 2015 Professional
   - cmake 3.3.1 used to generate the files
   - Windows 7 Enterprise</p>
  
  <p>Thanks,
  Jason</p>