Warn when user wants to configure properties in way it is not fully supported

I was quite surprised that even i switched on checkstyle.configurationFile changes were applied for all file. I though this is sputnik error but it seems to be lack of support. I added some validation so nobody won't be surprised :)
I am not sure if this is a good direction. There will be more options as sputnik grows. It would not be good if we have boolean property for each option. Maybe it would be better to have supports(GlobalOption) method.

This change is also incomplete, because there is a scoring feature that is not supported with Stash connector. We don't warn user about that.