* If no config animation, start paused and set one when first clicked (showControls only).
* Updated player editor to 4.0.
* Don't name example index.html to make it easier to reach other files in same dir.
* Adjust CSS.
* Updated config doc comments.
* Check undefined without typeof. Discussion: https://stackoverflow.com/a/22053469/187883
* Use transparent bg color by default if alpha is true.
* Set bg color on parent to avoid flash.
* render->create (so it doesn't seem like it's about drawing).
* Sorted members.
* Use addEventListener, else only the last player event handler is used.
* Set the initial animation when loaded, not whenever track 0 is empty.
* If an animation is not specified, play an empty animation.
* If an animation is set in success(), don't set any animation.
* Don't clearTracks in setAnimation, don't use AnimationState in calculateAnimationViewport -- those prevent mixing.
* setAnimation returns the TrackEntry.
* Added addAnimation and setViewport.
* Expose play() and pause().
* Keep control bones inside the canvas.
* LoadingScreen scales down.
* Set minimal CSS so no external CSS is needed when !showControls.
* Use screen instead of world coordinates for control bone hit detection, so it works at any size.
* Choose closest control bone instead of last.
* Rendering, added support for separate color/alpha src blend funcs.
* LoadingScreen, set camera zoom to fade out and black flash, use PMA to fix ringing artifacts when scaled, fade in to help hide dropped frames as page loads, use separate color/alpha src blend funcs to properly blend quad when loading screen fades out, oxipng PNGs.
* Moved some private constants out of their class to avoid class name prefix.
* Player, clean up full pass OCD town, showError throws when possible so stacktrace isn't lost, added showLoading to config, don't create UI when !showControls, removed findWithId (id is unique for entire document), use built-in for findWithClass/contains, var->let, don't clear screen twice during loading, other minor stuff.
* Removed # parsing from SpinePlayer, replaced with config.jsonField.
* Refactored AssetMananger to split downloading from asset creation.
* Allow Downloader to be specified in SpinePlayer config so multiple players don't download the same assets.
* Added AssetManager#loadJson so the text is only parsed once.
* TextureAtlas is still parsed multiple times. :(
* AssetMananger clean up, catch more errors, log error, don't keep rendering after an error.
* Added missing CurveTimeline#shrink calls. c and cpp got BOZO comments until the method is added.
* SkeletonJson#readCurve clean up.
* ts, use shorthand for null checks.
* csharp, don't use unnecessary hasNext local.
AnimatinState.setAttachment was directly setting the slot.attachment field instead of calling the setter. This caused the deform array from a previous attachment to linger around and be applied to the current attachment incorrectly.
