never Serial.print (except verbose)

[quartzjer]

There were quite a few places we were printing direct to serial and those commands wouldn't work via hq, this catches all those cases.

As a result of this change:

• pin.status table format is converted to json as a result, example output
• any sp(float,precision) will now print out the float properly
• a power.volts script command was added that prints the float value of the voltage