title: Running sonar analysis with mvn sonar:sonar ignores sonar-project.properties
body: <p>Latest 3.3 sonar-maven-plugin and 5.6 LTS as web server.<br>
  Running sonar analysis with <code>mvn sonar:sonar</code> 
  ( <a href="https://docs.sonarqube.org/display/SCAN/Analyzing+with+SonarQube+Scanner+for+Maven" rel="noreferrer">Scanner for Maven</a> )<br>
  ignores <code>sonar-project.properties</code> file. (with many parameters <a href="https://docs.sonarqube.org/display/SONAR/Analysis+Parameters" rel="noreferrer">https://docs.sonarqube.org/display/SONAR/Analysis+Parameters</a>)</p>
  
  <p>Is it that the expected behavior?<br>
  So do I have to configure all sonar parameters within <code>pom.xml</code> files?</p>