* Add mouse grab
We now also send mouse movement events only to the interested view.
* Add deprecation messages handler
* Make various `View`s respect `on_mouse_left`
* `StatusView`
* `TitleView`
* `TreeView`
* `ToolbarView`
* Fix scrollbar in `TreeView` not updating
We were in some cases sending outdated mouse positions to the scrollbar,
which made it think that the mouse was hovering it.
This also updates the hovered item more responsively during scroll.
the original hamburger menu icon is confusing. It is not a menu
and clicking it doesn't do anything. There is no reason why
we can't draw lite-xl's icon in place of that.