Fix more init sequence for nanofury.
Set value of gpio pins to low on closing nanofury.
Random libbitfury changes.
spi_txrx should always send and receive the same size message
Minor correctness change in spi_add_data
Fix spi transfer data size transmission mistakes.
Status 0x30 should never happen with spi transfers.
Remove inappropriate extra config reg in nanofury setup.
Move spi init code to libbitfury
Add bitfury detection loop to nanofury startup
Cancel any spi transfers on nf1 close
Set atrvec only once and use a local array for each device's work.
Pad all larger spi transfers to 60 bytes since intermediate sized ones make it expect more data.
Avoid bin2hex memleak when we start getting nanofury nonces