12.1.5

- Fixed bug that could cause zero-duration tweens at the very beginning of a nested timeline not to return to their beginning values if the playhead of the parent timeline goes past the nested timeline's startTime, and then goes back to EXACTLY on top of the startTime, and then before it.

- Improved GC, protecting against a very particular scenario where a user writes bad JS code that maintains a reference to a timeline.

- Fixed issue that could cause TweenMax.killAll() to go to the end of a tween instead of its beginning when it's reversed and the "complete" parameter is true.

- Changed LoaderMax so that it doesn't URL-encode underscores since Facebook uses them.