Things worth noting:
* When a fullscreen view unmaps, the check to unset fullscreen on the
workspace has been moved out of view_unmap and into container_destroy,
because containers can be fullscreen too
* The calls to `container_reap_empty_recursive(workspace)` have been
removed from `container_set_floating`. That function reaps upwards so it
wouldn't do anything. I'm probably the one who originally added it...
* My fix (b14bd1b0b1) for the tabbed child
crash has a side effect where when you close a floating container, focus
is not given to the tiled container again. I've removed my fix and
removed the call to `send_cursor_motion` from `seat_set_focus_warp`. We
should consider calling it from somewhere earlier in the call stack.
Implements the following commands:
* move scratchpad
* scratchpad show
* [criteria] scratchpad show
Also fixes these:
* Fix memory leak when executing command with criteria
(use `list_free(views)` instead of `free(views)`)
* Fix crash when running `move to` with no further arguments
