Merge pull request #8 from bmwiedemann/ost

fix 2 problems in backend/vbox
fix displaymanager login on rescue cd
fix various test failure during RAID partition test stage in GNOME Lice image
no bootloader with iPXE
add usbnetpower8800 support
kvm2usb: only turn on machine before reset if needed
kvm2usb: add description and edid upload details
kvm2usb: convert screendump to tinycv style
require lower similarity on noisy HW

kvm2usb VGA capture has some noise in the lower image bits
pushing the similarity of identical images to 44.9