put back the inheritable_metadata list into the XModuleDescriptor class. Also extend the metadata_inheritance test case

studio - adding in info icon to page intro help and making icon classes consistent in all new references

Also omit portal and terrain, which are used for the lettuce testing framework.

:-(

studio - page headers: added in logic to style page actions' height based on title having a subtitle or not

studio - soft landing: changed strong elem colors to be more subtle since we're not using new nomenclature