Throw Errors in case components do not fit into container

Hi bramstein,
thanks a lot for you fine library. I will use the flow layout for my project. But for my usecase it would be helpfull if I can see immediatly if the components I want to enter into a container do not fit into it. So I modified the flow layout to throw an error, if this happens. If you are appreciate such changes, I think I can also create such Errors for the other layout-algorithms.

I am looking forward to work with you. :)
Fonzy