Updating GSAP to 1.13.0 [author]

- Added new xPercent and yPercent special properties to CSSPlugin so that you can do percentage-based transforms in addition to px-based ones. Yes, you can combine them like {x:200, xPercent:-50}.

- Added support for document.querySelectorAll() as a fallback when a regular selector engine (like jQuery) isn't present. Previously, getElementById() was used, and it still is when document.querySelectorAll() isn't available.

- Significantly improved compatibility with AMD/RequireJS and CommonJS/Node/Browserify.

- Added "onAutoKill" callback to ScrollToPlugin so that you can have a function called when the user initiates a scroll in the middle of a tween.

- Worked around a very rare rounding issue on certain Microsoft devices that could cause a Draggable not to function properly.

- Fixed issue that could cause values in a timeline to render immediately AFTER its onComplete when a seek() is performed to the very end and the tween hadn't initialized yet (related to the "lazy" feature that defers rendering by default)

- Fixed bug that could cause easeParams not to work properly when the ease is passed as a string instead of a function.

- 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.