Keyboard navigation and autoScroll

[Koloto]

The core of the keyboard navigation is navigate method. It calls makeVisible and then setFocus/setActive. makeVisible calls scrollIntoView in its turn. But if option autoScroll is specified setFocus and setActive also call scrollIntoView. So scrolling runs two times. Look at the sample-scroll.html (before this PR). You can see that the tree shakes a little while scrolling with a keyboard.

Also I suppose that keyboard navigation should take into account autoScroll option. When autoScroll is off keyboard navigation must not scroll the tree. Now it always scroll. I handle activate event, execute some custom logic there and then call scrollIntoView explicitly. But keyboard navigation scrolls extra time and I can't turn it off.

So I propose to call makeVisible({scrollIntoView: false}) in navigate method. If autoScroll is true, setFocus/setActive will scroll later.

[mar10]

will merge, thanks. Let's see what happens...