JSON: display (Javascript)

Out of time for today, but hopefully is relatively self-explanatory. Will endeavor to fill this in soon.

Quick notes:

• Any property in display.json which has a capital J and an underscore as the start of the key (J_parent) is expecting a complete jQuery selector (ie, .myclass) whereas properties which seem to be asking for a selector without the J_ want the plain value (myclass).
• use when set to false for any of the functionality objects will turn that off; set to false at the top of the JSON will stop the JS from being enqueued.