Scroll to cursor function is too greedy

[rocketraman]

When the editor is re-rendered (could be because a remote change was received, or for some other reason like a focus change), if the local editor has been scrolled via the scroll bar so that the local cursor is invisible, the rerender causes the local editor to modify the scroll position so that the local cursor is visible.

The automatic scroll behavior should only be enabled for cursor-based navigation or editing.