move instance api into own file

change jsonbuilder to fire list of all nodes including current instead of keeping current separate from ancestors
done that now
put lines back into build script
move more logic from adding a new path from the instance api and into the controller
Change jsonBuilder from taking a couple of callbacks (which were always just the notify of an event bus anyway) to just taking the event bus. Simpler.
Make jsonBuilder a tiny bit simpler by just giving it a notify function not the whole bus
Make controller (very) slightly more dependency injection-y
+doc
update src readme to list new file
remove comment that no longer applies