JSONRPCImporter: kill created instances at stop
JSONRPCImporter: add new test for graceful stop
Improving test code

Removing duplicated classes, moving shared initialization for the parent class
fix color change bug in philips hue
Moving test utilities for a test classifier proj.

Code not placed into test are counted as code to be tested, so little by little we are moving test util classes into test projects, so they are not counted in test statistics by sonar