title: Reduce log level in Sonar 2.1.x
body: <p>I have a Maven 3.x build that uses Sonar 2.1.x for quality control. The maven-sonar plugin is used from inside Jenkins to run the Sonar checks.
  During the Jenkins build, when Sonar kicks in, it logs A LOT of not so useful information at INFO level:</p>
  
  <pre><code>[INFO] [15:29:14.195] Java version: 1.6
  [INFO] [15:29:20.853] Execute PMD 4.3 done: 6658 ms
  [INFO] [15:29:20.853] Sensor PmdSensor done: 6658 ms
  [INFO] [15:29:20.854] Sensor ProfileSensor...
  [INFO] [15:29:21.186] Sensor ProfileSensor done: 332 ms
  [INFO] [15:29:21.187] Sensor ProfileEventsSensor...
  [INFO] [15:29:21.190] Sensor ProfileEventsSensor done: 3 ms
  [INFO] [15:29:21.190] Sensor ProjectLinksSensor...
  [INFO] [15:29:21.192] Sensor ProjectLinksSensor done: 2 ms
  [INFO] [15:29:21.192] Sensor VersionEventsSensor...
  [INFO] [15:29:21.198] Sensor VersionEventsSensor done: 6 ms
  [INFO] [15:29:21.198] Sensor Maven dependencies...
  [INFO] [15:29:21.261] Sensor Maven dependencies done: 63 ms
  ...
  </code></pre>
  
  <p>The log is quite big. I have been trying to find a way to set the log level to WARN with no luck. Any idea?</p>
  
  <p>Thanks!</p>