PID-tuning tab: Sending PID-factors should not start PID-mode

[tomasaas]

Summation: The thrusters should not begin to move just because PID factors are sent to MCU. The thrusters should only move (excluding pilot commands' addition) when the PID is active.

The “send to MCU” button for changing the PID factors also starts the PID controller.

I suspect that the Nucleo does not currently have two separate modes: PID and non-PID. There should probably be a flag, and the Nucleo should behave differently depending on which mode is selected.