Refactor of prompts and the displayhook....
Refactor of prompts and the displayhook.
* Renamed CachedOutput to displayhook.DisplayHook.
* Added methods that DisplayHook.__call__ uses to do its work.
These methods can now be overridden for the ZMQ kernel.
* Removed all hooks (result_display and generate_output_prompt)
that the outputcache was using. We need to add these back in
once we figure out what to do about hooks in general.