The Great Zerolib Schism of 2019

Most importantly, I've taken all of the flixel related utilities out of zerolib and moved them here!

Second, all of the classes have been reorganized:

• classes in zero.ext.flx have been moved to zero.flixel.extensions
• classes in zero.flxutil.ecs have been moved to zero.flixel.ec
• some classes in zero.flxutil.editors have been moved to zero.flixel.ui
• classes in zero.flxutil.util have been moved to zero.flixel.utilities
• ParticleEmitter has been moved from zero.flxutil.sprites to zero.flixel.ec
• PlatformerAnimation has been renamed to PlatformerAnimator

Third, some things have been removed:

• ZomeLoader has been removed because ZOME is being deprecated.
• OgmoLoader has been removed because reasons.
• PlatformerDolly has been removed and replaced by zero.flixel.utilities.Dolly

Finally, some new additions!

• Lots of changes all around!
  • additions to PlatformerJumper and PlatformerWalker that extend functionality
  • added the ability to prioritize components (override Entity.update_components() and use update_components_by_priority()).
  • some more I can't remember :P
• As mentioned above, Dolly replaces PlatformerDolly with a new, more flexible dolly system.
• FlxOgmoUtils added - more info on this later!

This is a big update that breaks a bunch of stuff, so I hope it's worth it :)