Emitter.setScale has a new 'rate' parameter which allows particles to change in scale over time, using any Easing value or timescale.
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.