- Support some site screwing document.scrollingElement

- Fix problem which wrong target is obtained from keyboard event on elements in ShadowDOM (causes space key misbehavior on input box in ShadowDOM)

- A peace of adjustment for working better on current Firefox

- Fixed hiccups when scrolling heavy contents. (explicitly add listener as un-passive to be enabled preventDefault() on wheel event handler)

Fix broken overlay problem on some site when enabling option which added last update

- Added option to apply an instant fix found for scroll disability problem sometimes we face to on current versions.
- For IFrame handling, decided with popularity, we support high dpi display rather than browser zooming, since both of them are observed by one parameter devicePixelRatio.

- more fix of conflict of scrollBehavior:smooth CSS style

- more mending of conflict on sites with scrollbehavior:smooth

Improved "scrollbehavior: smooth" canceler fixes glitchy behavior caused by collision of smooth scrolling functionality on so few pages.

- upcoming shadow DOM preparation
- fixed: glitch when switching scrolling target while scrolling
- mended: glitch on page of gigantic height

- Fix bounce animation glitch in a rare case of HTML layout.
- Fix missing mouseup event problem on Mac/Linux. Found a better thing to look at.
- Now blacklist hit of top frame also disables scrolling in iframes no matter what URL of itself is.

- Bouncy edges are now by Web Animation API not by element insertion. Bouncy edges are available on flex layout pages such as StackExchange.
- Instead of setTimeout(), requestAnimationFrame() is used for animation update. This brings a remarkable improvement of scroll animation.

- Handle Firefox DOM issue that default value of "overflow-y" of textarea returns spec precise "visible", behaves like "scroll" though.

- Keyboard events listening on proper phase (affects keyboard shortcuts on Youtube video pane)

- More precise and optimized inter-frame events transferring
- Meta-ArrowUp/Down keys support