title: SonarQube analysis mode: preview vs issues
body: <p>Which are the key differences between these <strong>preview</strong> and <strong>issues</strong> modes of SonarQube (greater than 5.2) analysis? </p>
  
  <p>Considering <a href="http://docs.sonarqube.org/display/SONAR/Concepts" rel="noreferrer">http://docs.sonarqube.org/display/SONAR/Concepts</a> the main differences between <strong>publish</strong> and <strong>preview</strong> is that <strong>preview</strong> reports only issues (no measures) and no report is pushed back to the SonarQube server; this idea is clear. But what about <strong>issues</strong>? It is written that <strong>issues</strong> is the same as <strong>preview</strong>, but should be used only for tools development. I'm a little confused, what do they mean by tools?</p>