Renamed TweenViewportX/YByDistance to TweenViewportX/YBySpeed as it should be.
Added ability to independently control x and y coordinates of GUI, GUI controls, characters, and objects, both by seconds and by speed.
Migrated loose functions to static calls in Tween struct, added WaitForLongest, SetTimerForLongest, and SetTimerWithSeconds helper functions, simplified the internals of Tweening Viewports. TweenViewportPosition -> TweenViewport, TweenGamma -> TweenSystemGamma.