should the screen attribute in Layout really be optional? #32
Description
In the EAR reference code, the screen is always present, but set to some default dimensions if not specified.
Handling the case where there is no screen (and skipping screen-related processing) might be desirable, but is non-standard -- should we get rid of the boost::optional wrapper (changing the API), or just set it to a default value and complain if it's reset to boost::none by the user?