Added gestures, throttle less sensitive, etc...

Added KeyTap gesture to enable/disable rudder control ("3" still works
aswell) ;
Circle gesture for a potential "flip" later on (doesn't do anything
right now) ;
copter.throttle value changed to be less sensitive and thus easier to
control ;
Changed stabilisation from 0.70 to 0.65 (still needs more calibration
though) ;
Changed text from "Control : desactivated" to "Control : Inactive" as it
was incorrect.
Removed "println(hand_position);" as it flooded the console