Every workspace was tiled with the default padding of 5 pixels around and
between its tiles, and the work area offsets could not be set. The padding
commands set a workspace's own workspace padding and container padding, by the
indices of its monitor and itself or for the focused workspace, and the adjust
commands make the focused workspace's larger or smaller.
`global-work-area-offset`, `monitor-work-area-offset` and
`workspace-work-area-offset` keep a part of the work area free of tiles, and a
workspace's offset now wins over its monitor's, which wins over the global one.
A monitor's window-based offset applies while the workspace in front has no more
windows than the monitor's limit, and `toggle-window-based-work-area-offset`
turns it off and on for the focused workspace.
The vm-commands sweep sets and resets every offset and padding.
