allow changing the owner via the canvas

[prabirshrestha]

would like to use the canvas ui to change the owner instead of using the json. easier when the json file is large.

[bvaughn]

That's a neat idea, but I'm not looking to make the Canvas interactive in any way (other than tooltips). Data goes in as JSON and gets displayed in the Canvas only.

(Feel free to fork and add the behavior you're describing though!)