This version of libusb is required by the soon-to-be-released gphoto2.
- Add support for MacOS X (Darwin)
- Fix endianess correctly where applicable on all OS'
- Return bytes written/read for control message (BSD)
- Tweak documentation build
- Fix bug when usb_find_devices was called multiple times (Linux)
- Fetch descriptors for all devices when we can and parse them