title: Qt Installer Framework Offline Update - how?
body: <p>I've been able to create an installation for my software. However, I can't figure out how to create another installer which could update previous installation.</p>
  
  <p>I have updated component versions, software version and release dates, but whenever I run second installation over the folder with pre-installed software - I'm getting <code>The folder you selected already exists and contains an installation. Chose different target for installation.</code></p>
  
  <p>Any hint on how to update an existing installation using Qt installer Framework would be very welcome!</p>