Transitional and mode system overhaul

[scriptorum]

Note on Flaxen.removeTransitionedEntities: I like this idea, but I don't like how it's implemented.

[scriptorum]

Also note on setNode: Be able to specify matching and excluding kinds here.

[scriptorum]

I really need to rethink modes and handlers and transitional entities. Ideally it would support nested states as well as replacement states, the handler would be notified of changes so new entities can be created, the handler can receive parameters to dictate variations in its setup, and entities will transition automatically.

Further this should be a simplified process. Right now you can add Transitional components to all entities by eschewing newEntity and using newSetEntity with component sets that have the Transitional pre-loaded into the set. Would like this to all work cleaner.

[scriptorum]

I ken spelz.