atusb: cleaned up USB schematics
atusb: cleaned up USB schematics

- usb.sch: renumbered test points for serial programming
- usb.sch: moved everything down to make room on top
- usb.sch: moved description of pad placement near the pads
- usb.sch: added footprint of U1

cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan