USB devfs patch

Hi,


Below is a patch from Rink Springer to change the new USB stack to use
devfs device nodes.  I have tested this with a usb mouse and I am hoping
people with other devices can test too, in particular scanners (sane
app) and lpt ports.

This also removes the custom permissions from usb and usbconfig.

http://people.freebsd.org/~thompsa/usb-cdevs.diff


cheers,
Andrew