grio is a modified rio that adds hubfs integration, an extra user
selectable command in the menu, and appearance options.  grio expects
hubfs to be installed.  If an available hubfs is not mounted at
/n/hubfs, it starts one.  It uses /srv/riohubfs.username for the new
hubfs.  Additional options: the -x argument sets a command (default
/bin/acme), -a provides an argument to it.  Colors are defined by 8
digit hexidecimal numbers.  -c sets background color, -t the text
color, -u the window color, -y the border color of active windows, -z
the border color of backgrounded windows.  The width of borders can be
set with an integer parameter for -w. -e removes the 'exit' option from the menu.

Example: grio -x /bin/stats -a -elm -c 0xaabbccff -y 0x11111111 -w 2