Give each animation a callback function via animationConfig

[AndreasGalster]

I find myself dealing with really, extremely ugly "meh sort of works but I was really lucky there I still found it" workarounds when dealing with many Polymer animations. Very often you need to perform a certain action after an animation. Problem is: You only have one 'callback', which is the neon-animation-finish event. This creates a lot of problems when having to create different actions based on which animation just has finished playing, since neon-animation-finish doesn't care which animation finished playing.

[cdata]

Thanks for the request. I think ideally we would facilitate this through some kind of event.