* Game.Config.roundPixels property added to prevent sub-pixel interpolation during rendering of Game Objects in WebGL and Canvas.
* Load.plugin now accepts a class as an argument as well as a URL string (thanks @nkholski)
* Tween.complete will allow you to flag a tween as being complete, no matter what stage it is at. If an onComplete callback has been defined it will be invoked. You can set an optional delay before this happens (thanks @Jerenaux for the idea)
* The Headless render mode has been implemented. You can now set HEADLESS as the `renderType` in the Game Config and it will run a special game step that skips rendering. It will still create a Canvas element, as lots of internal systems (like input) rely on it, but it will not draw anything to it. Fix #3256 (thanks @rgk)
* The SceneManager has a new method: `remove` which allows you to remove and destroy a Scene, freeing up the Scene key for use by future scenes and potentially clearing the Scene from active memory for gc.
* InputManager.updateBounds wouldn't correctly get the bounds of the canvas if it had horizontal or vertical translation in the page, causing the scale factor to be off (and subsequently input values to mis-fire)
* The implementation of `topOnly` within the Input Manager had broken the way drop zones worked, as they were now filtered out of the display list before processing. Drop zones are now treated on their own in the Input Plugin meaning you can still have `topOnly` set and still drop an item into a drop zone. This indirectly fixed #3291 (thanks @rexrainbow)
* InputPlugin.clear now properly removes a Game Object from all internal arrays, not just the _list.
* InputPlugin.processOverOut no longer considers an item as being 'out' if it's in the internal `_drag` array.
* When a Game Object is scaled, its Arcade Physics body was still calculating its position based on its original size instead of scaled one (thanks @pixelpicosean)
* AnimationComponent.play now calls `setSizeToFrame()` and `updateDisplayOrigin()` on the parent Game Object in order to catch situations where you've started playing an animation on a Game Object that uses a different size to the previously set frame.
* If you set `transparent` in the Game Config but didn't provide a `backgroundColor` then it would render as black. It will now be properly transparent. If you do provide a color value then it must include an alpha component.
* You can now pass normal Groups to Arcade Physics collide / overlap, as well as Physics Groups. Fix #3277 (thanks @nkholski)
* Texture.get has been optimized to fail first, then error, with a new falsey check. This allows you to skip out specifying animation frames in the animation config without generating a console warning.
* The `setFrame` method of the Texture component has been updated so that it will now automatically reset the `width` and `height` of a Game Object to match that of the new Frame. Related, it will also adjust the display origin values, because they are size based. If the Frame has a custom pivot it will set the origin to match the custom pivot instead.
* Fixed issue with vertex buffer creation on Static Tilemap Layer, causing tilemap layers to appear black. Fix #3266 (thanks @akleemans)
* Implemented Static Tilemap Layer scaling and Tile alpha support.
* Fixed issue with null texture on Particle Emitter batch generation. This would manifest if you had particles with blend modes on-top of other images not appearing.
* The entire codebase now passes our eslint config (which helped highlight a few errors), if you're submitting a PR, please ensure your PR passes the config too.
* The Web Audio Context is now suspended instead of closed to allow for prevention of 'Failed to construct AudioContext: maximum number of hardware contexts reached' errors from Chrome in a hot reload environment. We still strongly recommend reusing the same context in a production environment. See [this example](http://labs.phaser.io/view.html?src=src%5Caudio%5CWeb%20Audio%5CReuse%20AudioContext.js) for details. Fixes #3238 (thanks @z0y1@Ziao)
* The Webpack shell plugin now fires on `onBuildExit`, meaning it'll update the examples if you use `webpack watch` (thanks @rblopes)
* Added `root: true` flag to the eslint config to stop it scanning further-up the filesystem.