cl-libusb provides an easy interface to libusb-0.1. There are two
systems/packages: libusb-ffi, which provides a (somewhat lispified)
ffi to libusb-0.1, and cl-libusb, which provides an easier interface.

Buffers are dealt with using unsigned byte arrays from grid and
foreign-array.

libusb-ffi (and thus cl-libusb) is not complete, but should be usable.

Tested and found to work on:
linux amd64 (sbcl)
Windows XP Professional 32-bit (clisp, mingw)

To do: Antik is larger than what cl-libusb requires; use static-vectors
instead.