PrimaryFeather/Starling-Framework — pull request #319 by ericsoco (2013-04-11 05:07:51+00:00)
Title: added progress accessor to Tween

find a Tween's progress, as determined by its transition function, from
0 to 1. previously, this was calculated only within animate() (and was
inefficiently calculated separately for each tweened property).

(moved this feature to a different branch, to disambiguate from my other open (TextField) pull request...)