Getting monitor resolutions when xorg isn't running

[David Sveningsson]

Hi, is it possible to get a list of supported resolutions for a monitor, 
similar to using xrandr, but even if xorg hasn't been started?

It doesn't matter if it is an existing tool or if it is only possible by 
using some library routines. I could live with having to start some 
subset of xorg as long as it doesn't actually show anything on the monitors.