apm_saver uses the apm_display() routine from the apm system to
"suspend" the "display" part of the machine.
This is beneficial for some laptops (or other machines with
non-traditional displays) that choke on the 'green' saver's
effect.
Another way of looking at this is that it's the same as a screen
saver that does an 'apm -d 0' to blank the display and an 'apm -d 1'
to bring it back. One probably ought to use these commands to make
sure the effect will be correct before using it unattended.
