* Add methods `Invulnerable() bool` and `SetInvulnerable(bool)` to the
Actor API accessible in JavaScript (e.g. `Self.SetInvulnerable(true)`)
* The Anvil is invulnerable - when played as, it can crush other mobs by
jumping on them but is not defeated by those mobs at the same time.
* Anvils don't destroy invulnerable mobs, such as other Anvils.
* Bugfix: the Electric Door is considered to be opened from the first
frame of animation when the door begins opening, and remains opened
until the final frame of animation when it is closing.
* New cheat code: `megaton weight` to play as the Anvil by default.
* 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.
* If the player runs the PlayAsBird cheat they shouldn't be able to win
a high score on a level, so at level startup it detects whether the
DefaultPlayerCharacterDoodad has changed from default on a level that
doesn't use the Start Flag to set a specific doodad - and immediately
marks the session as cheated
* New doodad: Invisible Warp Door
* All warp doors require the player to be grounded (if affected by
gravity) to open them. No jumping or falling thru and opening
a warp door mid-air!
* Title Screen now randomly selects from a couple of levels.
* Title Screen: if it fails to load a level it sets up a basic
blank level with a wallpaper instead.
* New developer shell command: titlescreen <level>
Opens the MainScene with a custom user level as the background.
* Add Auto-save to the Editor to save your drawing every 5 minutes
* Add a MenuBar to the Play Scene for easier navigation to other
features of the game.
* Doodad JS API: time.Since() now available.
* Added the Death Barrier to Play Mode to catch players from falling off
the map and then falling indefinitely, especially on Unbounded maps.
* The Death Barrier is set 1,000 pixels below the lowest point on your
map. If the player falls here they get a death message: "Watch out for
falling off the map!"
* Added cheat codes to change the default Player Character doodad, as a
way to force play as a different character (for levels which don't
specify a custom character):
* Play as Bird: fly like a bird
* Play as Blue Azulian: the cell
* Play as Thief: play as thief
* Reset to default (Boy): pinocchio
* The pattern textures for level palettes have been brightened and work
better with bright colors.
* The three default palettes for new levels now have patterns applied to
each of their colors.
* Bugfix around resetting keybind states for Zoom In/Out, Scroll to
Origin and Reset Zoom Level bindings.
