This allows the title's texture to always be the full width of the text,
and clipped at render time according to the desired width (eg. tabs...).
As an added bonus, the texture no longer needs to be updated when
containers are arranged.
Before freeing sway_output, NULL the wlr_output reference to it. Check for that
NULL in layer_shell handle_destroy. Don't damage null container in unmap.
Additionaly, terminate swaybg if its output is being disabled.
Replaces arrange_windows() with arrange_root(), arrange_output(),
arrange_workspace() and arrange_children_of().
Also makes fullscreen views save and restore their dimensions, which
allows it to preserve any custom resize and is also a requirement for
floating views once they are implemented.
The exact semantics of this command are complicated. I'll describe each
test scenario as s-expressions. Everything assumes L_HORIZ if not
specified, but if you rotate everything 90 degrees the same test cases
hold.
```
(container (view a) (view b focus) (view c))
-> move left
(container (view b focus) (view a) (view c))
(container (view a) (view b focus) (view c))
-> move right
(container (view a) (view c) (view b focus))
(container L_VERT (view a))
(container L_HORIZ
(view b) (view c focus))
-> move up
(container L_VERT
(view a) (view c focus))
(container L_HORIZ (view b))
(workspace
(view a) (view b focus) (view c))
-> move up
(workspace [split direction flipped]
(view b focus)
(container (view a) (view c)))
(workspace
(view a) (view b focus) (view c))
-> move down
(workspace [split direction flipped]
(container (view a) (view c))
(view b focus)))
Note: outputs use wlr_output_layout instead of assuming that i+/-1 is
the next output in the move direction.
(root
(output X11-1
(workspace 1))
(output X11-2
(workspace 1 (view a focus) (view b)))))
-> move left
(root
(output X11-1
(workspace 1 (view a focus)))
(output X11-2
(workspace 1 (view b)))))
(root
(output X11-1
(workspace 1
(container (view a) (view b)))
(output X11-2
(workspace 1 (view c focus)))))
-> move left
(root
(output X11-1
(workspace 1
(container (view a) (view b))
(view c focus)))
(output X11-2
(workspace 1)))
```
