Bug #3829: ITK module is actually needed for testing
Bug #3829: Fixed the context creation for Mac
Bug #3829: Making sure that all the CL extesnions are loaded
Bug #3829: Changed how the CL-GL compatibility is evaluated. Now it is hard-coded to true on Mac as there are no means to query CL_GL compatible devices before creating a context
Bug #3829: Disabling test that does not compile in MITK