Change "Quit RWind" key binding to "Super-S-Esc" because it was too easy to hit "Super-Esc" by mistake, especially when "Super-F1" changes the desktop.
add "" for 'minus', because of string-split
Now with fullscreen mode! (not yet added to config-simple to as to test it further).

Remains question: Currently implemented for the tiling policy, since it's automatic in stacking policy, but doesn't this code belong the workspace.rkt instead of tiling.rkt?
tiling policy now places dialog windows as floating windows and does not try to resize them
fix: better handling of dialog and fullscreen windows. Fullscreen windows now are like dialog ones: they are placed on top of the tiled windows
fix vocabulariy