* have explicit methods for changing the scroll position (delayed/smooth vs now/direct) that bubble up to the editor internals.
* have all other clients of ScrollableElement not use smooth scrolling

Use will-change to hint browser layers for the lines content and the margin layers instead of using translate3d ((Microsoft/monaco-editor#426))

Do not use translate3d in scrollbars, use will-change for scrollbar sliders instead (Microsoft/monaco-editor#426)

 * Apply smooth scrolling in every scrollable element when mouse wheel scroll
   occurs

 * Apply smooth scrolling in editor view when large jumps occur
   (e.g. when the cursor is moved by pressing PageUp or PageDown)

Fixes Microsoft/monaco-editor#2: Fix scrollbars, context menus, mouse operations and content widgets layouting when editor is inside a position:fixed container