* 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.
* 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.
