* The title screen now loads the default maps from a LevelPack. The game
no longer ships with the Tutorial levels in the "levels" folder as
default; they are in the LevelPack so the "Edit Drawing" screen begins
as a blank slate for only user levels.
* Add the Zoo level to the Tutorial levelpack
* Bugfixes around changing the player character to work around clipping
issues if the character has changed height drastically.
* Switch from otto to goja for JavaScript engine.
* goja supports many ES6 syntax features like arrow functions,
const/let, for-of with more coming soon.
* Same great features as otto, more modern environment for doodads!
