* scrollLeft/scrollTop returned values of parent or even document root
Only the scroll of the node itself is returned. Otherwise 0.0.
* Scrolling via script had set viewport.
This resulted in other nodes appearing scrolled.
Now scroll_offsets are updated with correct node id.
These bugs caused other odd behavior like both body and
document.documentElement being scrolled or the view for scrolled
elements jumping.
284cb8aae8