Sub: AP_Motors6DOF: create get_throttle_in_bidirectional()

libraries/AP_Motors/AP_Motors6DOF.h

@@ -51,6 +51,10 @@ public:
 
     bool set_reversed(int motor_number, bool reversed);
 
+    // This allows us to read back the output of the altidude controllers
+    // The controllers are in charge of the throttle input, so this gives vehicle access/visibility to the output of those controllers
+    float get_throttle_in_bidirectional() const { return constrain_float(2*(_throttle_in - 0.5f), -1.0f, 1.0f); }
+
     // var_info for holding Parameter information
     static const struct AP_Param::GroupInfo        var_info[];