Support max31855 thermocouple over spi.
Limit SPI transaction to 16 bits.
Some error handling cleanup.
Changed config parameter name.
Individual tower radii.
Merge branch 'delta_parameters' into edge
Added buffer for averaging of measurements to improve PID robustness.

Also ignore occasional failed measurements from the thermocouple.
Formatting changes.
Merge branch 'thermocouple' into edge