TestXmlDisplayer logs if it does find xml output files.
TestXmlDisplayer returns if it has found any test result or not.
The default output directory for test results is "test-results" for every test (whatever name it has).
Improved the tests for JavaTestModel.
Fixed JavaTestModelBuilder when the test xml output dir is customized.
ContextAwareCommandCompleteAction now returns a ContextAwareCommandCompleteListener, so that it can retrieve some information about the executed task.