Update NEWS.
Drop logging level for failed to connect to stratum to verbose mode only since we hit it regularly.
Show the error number as well as the description in erroring bulk transfers.
Retry up to USB_RETRY_MAX times to clear a halt condition before failing.
Do not attempt to clear a usb halt before sending the cancel message since all transfers should normally be cancelled before attempting to clear a halt condition, and only change the return message to a timeout if it's consistent with a cancellation.
Add a small amount to the usb timeout before cancelling to allow for a regular usb polling interval to pass.
Avoid calling get_statline on exit.
Avoid calling get_statline_before on exit to avoid trying to use it on drivers in an indeterminate state.
Make pthread conditional timeouts handle all bulk usb transfer timeouts performing libusb_cancel_transfer, disabling timeouts within libusb itself.
Specify interfaces in order on bitfury.