Porting UPower to libusb1

[Richard Hughes]

I've just committed this:

commit 2b826a316954eec9951b9bf98b853560cfd70828
Author: Richard Hughes <richard at hughsie.com>
Date:   Tue May 18 09:37:17 2010 +0100

    Port UPower to libusb1 to avoid crappy unfixable crashes

I would appreciate some testing, especially if you get semi-random
crashes and the backtrace points squarely at libusb. Thanks.

Richard.