Add Servo::move() to servo.cpp

move(pin, angel) - Sequence of attach(pin), write(angel),
                   if DEACTIVATE_SERVOS_AFTER_MOVE is defined waits SERVO_DEACTIVATION_DELAY, than detaches.

As we have jitter on the servos during moves of the steppers, and detaching them improves this behaviour,
the usual sequence to handle a servo movement is:
attach(pin)
write(angel)
delay(until the servo finished the move)
detache()

Here a function to handle the complete sequence.