title: Ignore/only show errors/warnings from certain directory using CMake
body: <p><strong>main question:</strong> Is there a configuration for cmake, to show or ignore compiler warnings/errors only from a certain directory?</p>
  
  <p><strong>alternative solution:</strong> How can I toggle this in QtCreator?</p>
  
  <p><strong>background / motivation</strong>:
  I'm working on a bigger CMake-project and want to focus on warnings and errors only from my subproject. I'm working with QtCreator and it annoys me to look for "my" errors/warnings under a pile of foreign ones.</p>