htdp/image or htdp/universe (big-bang) missing features

[stchang]

big-bang missing handlers (according to big-bang docs)

• name

big-bang handlers not completely working

• stop-when last-render fn crashes due to undefined obj #303
• on-draw: first world is not drawn when no on-tick handler is supplied #304

htdp/image missing features

• support htdp pen #334

[leiDnedyA]

Even though the documentation says the name handler sets the title of the canvas, in my experience it seems like the main use case is to provide a label for a big-bang instance's iworld to be used by a universe via the iworld-name function.

I implemented it this way in peer-universe (#331), but I also made it so that it sets the title of the webpage (aka the tab label) to the provided name. I'll get to work on adding the handler and make a PR when it's ready.