This is trivial to support and allows basic customization without
running a layer-shell program such as swaybg. This is especially useful
in low memory situations.
- wait until map to send tiled state
- only set toplevels with no parent to tiled (toplevels with a parent
are generally popup-like things such as a file chooser or yes/no prompt)
- track dimesions and offset of the surface and take offset into account
for rendering.
This means that floating views can be (partially) obscured by normal
views if they are low in the stack, and that the "full" layout will
work a little nicer as the focused view is always the top rendered.
