RFC: nuke pcidevs and usbdevs

[Hasso Tepper]

http://leaf.dragonflybsd.org/~hasso/killing-usb-defines-idea.patch

This patch illustrates what I intend to do in the USB code regarding
usbdevs nuking. I wanted to avoid increase of ambiguity with nonobvious
hex numbers to make it clear that these are vendor/product id's. The
patch illustrates all cases: occasional quirks like the one in the
umct.c, match tables like in the if_axe.c and umct.c and quirk tables
like in the umass.c.

While at it I intend to kill all custom "vendor and product pair"
structures (like in the if_axe.c and umct.c) and custom walkthrough
methods for arrays of these structures.

If you have comments, suggestions or objections, please speak up now.


-- 
Hasso Tepper