* Clean up unused msgpack code for levels and doodads
* Fix the cosmetic bug where actors in your level would display wrongly
when scrolling off the top/left edges of the screen: they used to
anchor at their own 0,0 coordinate and crop their width/height leading
to a 'scrolling' effect that didn't happen on the right/bottom edges.
The Default handler of the developer command shell now calls out to
RiveScript to match the user's message to a friendly reply. If
RiveScript returns NoReplyMatched then give the "command not found"
error.
