There should be an offline mode that allows limited functionality

[thehogfather]

As referenced here an offline mode should allow users to do everything except running the prototype, typechecking or saving documents

ref #188 #issuecomment-72176923

[PaoloMasci]

Regarding the ability to save documents, the offline mode could allow one to save documents locally (otherwise one is not able to save changes if the server is permanently down)