title: sonarqube 4.2 using clover for code coverage
body: <p>I am testing q Sonarqube 4.2 upgrade (currently on 3.6). I have so far been unable to get Sonar to use Clover for code coverage. There is now no option to set the coverage plugin (was under settings-> in 3.6) so I have set the property directly using -Dsonar.java.coveragePlugin on the maven build command for sonar.
  Even so, the build logs has this entry
      - Project coverage is set to 0% as no JaCoCo execution data has been dumped: /data/bamboo5.2.2-home/xml/build/APPCONFIGURATOR100-SONAR-JOB1/application-configurator/target/jacoco.exec
  which implies that Jacoco is being used for coverage. The sonar build fails with the following error
      - [ERROR] Failed to execute goal org.codehaus.mojo:sonar-maven-plugin:2.0:sonar (default-cli) on project application-configurator: Can not execute Sonar: Can not add twice the same measure on org.sonar.api.resources.File@4095349b</p>
  
  <p>What am I missing ? All help greatly appreciated.</p>