Continue to re-factor test and error handling. Remove final cases of Output/CanvasOutput globals.
Fix up a remaining Output usage in TipBar.
Start to improve organization of files by type of output.
Rename Output to LiveEditorOutput and CanvasOutput to P5jsOutput. Change them to Backbone views. Change some lingering non-relative DOM logic.
Handle P5js-specific postMessages. Also cancel the error delay all the time.