Emitter.setAlpha has a new 'rate' parameter which allows particles to change alpha over time, using any Easing value or timescale.
Emitter.bringToTop and Emitter.sendToBack are booleans that let you optionally set the display order of the Particle when emitted.
Emitter.particleAnchor allows you to control the anchor of emitted Particles. Defaults to 0.5 (same as before) but now under your control.
Emitter now emits Phaser.Particle objects instead of Phaser.Sprites, which can be extended as required.
Emitter has had various local properties removed that were already declared in Phaser.Group which it extends.
ArcadePhysics.Body.reset incorrectly set the Body.rotation to Sprite.rotation instead of angle.
Emitter.emitParticle resets the rotation on the particle to zero before emitting it.
Lots of fixes to the TypeScript definitions file (thanks as always to clark-stevenson for his tireless work on these)
Emitters now bring the particle they are about to emit to the top of the Group before doing so. Avoids particles hidden behind others.
ArcadePhysics.Body.setSize corrected to take the parameters as positive, not negative values.
ArcadePhysics.Body now checks the Sprite scale automatically and adjusts the body size accordingly (fix#608)
Emitter.particleClass can now be set to any object that extends Phaser.Sprite, which will be emitted instead of a regular Sprite.