Add "ghosts" ctl command (not really implemented).
Add "winsize" ctl command.
Ellipsoids now accept -l levelno option, in which case
"hide levelno"/"show levelno" applies to them.  Default is -1,
which means "show if any level is shown", but hidden by "hide all".
Scrap ghost maintenance.  Do that elsewhere instead.
Make "maxcomment" work properly.