Some basic set up of a tableview to browse current user's characters.
Changed the way related objects are added by setting the inverse relationship instead of trying to break into immutable ordered sets.  Also made a user required for CommandCreateCharacter.
Added more coverage to tests of relationships in ModelTests.
Connected some data to a table view and then re-worked how the Game object instance would access by UI.
Created InputHandler and InputHandlerDelegate class and protocol to separate out input mapping to commands and responses in UI once command sare complete.
Implemented transition to new InventoryViewController using segues.