Allow generating full coverage results with Jacoco and Sonar

The strategy is the following:

• Have a jenkins job that will execute: mvn clean install -Pcoverage. This will run unit tests and aggregate all test results in a global coverage file that Sonar will use to display IT coverage
• Configure that Jenkins job with a post build step to run Sonar. This will run the unit tests and allow to also display unit test coverage in Sonar.