Add two new functions to the libusb20 API and required kernel ioctls.
- libusb20_dev_get_iface_desc
- libusb20_dev_get_info
New command to usbconfig, "show_ifdrv", which will print out the kernel driver
attached to the given USB device aswell.
See "man libusb20" for a detailed description.
Some minor style corrections long-line wrapping.
Submitted by: Hans Petter Selasky