v0.9.9

Feature list:

1. Added comments to undocumented classses from the v0.9.8 release, i.e. PriorityQueue, the Heaps, ActionList, AStar, and others.
2. Added new Ease component, including implementations for easing transform parameters, EasePositionTo, EaseRotationTo, EaseEulerRotationTo, and EaseScaleTo, as well as a sample scene showing various uses of them.
3. Move easing files from Math to the Animation folder.
4. Updated readme to include various feature samples & gifs.

Bug Fixes:

1. Fixed HorizontalLine editor utility not drawing height correctly (it was always EditorGUIUtility.singleLineHeight.