screenblank envsys pseudo device

[matthew sporleder <msporleder%gmail.com@localhost>]

Hi, I wrote a pseudo device that presents an ioctl which triggers an
envsys event that will eventually make it to powerd.  My original plan
for this was to add the ioctl to screenblank so I could have powerd
run vbetool when it blanked the screen.

I have it basically functioning but before I got too crazy trying to
clean it up I was wondering if anyone else was interesting in this
sort of thing and if anyone can guide me on a less round-about way of
accomplishing this.

thanks,
Matt