Syntax: DEVICE svga [ args ]

  The svgalib driver supports the following arguments:

    modes             List available video modes
    -fg colour        Foreground colour
    -m n              Select a mode

  You can toggle between nodes with some magic svgalib key of which I
know not, or using PAGE; I have the line
      key pf1 del1 PAGE\N
in my startup2 macro, making the F1 key on my laptop generate the command
      del1 PAGE
and thus toggle for me.

NOTA BENE: This is an alpha driver. It assumes that you have installed
a recent version of svgalib (from sunsite or equivalent), and have
configured options.h and src/Makefile appropriately. This is NOT done
via set_opts as we don't want innocent bystanders to be hurt by this
code. The way that the svgalib is configured requires that sm be
installed owned by root and setuid -- a major security hole. I'll think
more about this when I get a chance. Maybe it doesn't matter on a laptop?

Known problems:

Switching to a different virtual console and back when in text mode,
and not saying
	device svga
before plotting may corrupt your graphics state, and require a reboot.
It seems to be OK to switch consoles in graphics mode.