#7 Arm/Disarm motor

[Samuel Cowen]

Presently the motor will go whenever the throttle trigger is pressed. It's a bit dangerous. There needs to be a motor arm/disarm function. There is a firelink packet for disarming and arming motors - firelink.make_motor_arm_packet()

The motor must be disarmed intially. This means throttle inputs will be ineffective. The motor should only be armed when the throttle is 0, the throttle down trigger is held AND the 'arm motor' button is pressed.