[TEST] Include integration tests, exclude UI classes for code coverage

The cobertura task(s) now include the integration tests in order to provide higher code coverage. Also, the UI classes (from the ui and dbdialog modules) are not instrumented or reported, this is because it is currently an unfair skew of the coverage metrics as the UIs are very difficult or impossible to test in a headless environment.

The CI job (http://ci.pentaho.com/view/Data%20Integration/job/Kettle-Code_coverage/) should now call the following:

ant -Djunit.maxmemory=2048M -Dmodule.list=core,engine clean-all resolve cobertura

It also does not need to collect test reports (Kettle-build does this), but should report coverage to CI and Sonar.