Pythonic API for linux's functionfs.

functionfs is part of the usb gadget subsystem. Together with usb_gadget's configfs integration, allows userland to declare and implement an USB device.

Requirements

• A linux-capable computer with a USB controller able to act as a device. Ex: Raspberry Pi zero, Intel Edison
• The linux kernel built with CONFIG_USB_CONFIGFS_F_FS enabled, plus all needed peripheral drivers, including the usb device controller.
• python-libaio, which itself depends on libaio.