AP_AccelCal: added active() method

libraries/AP_AccelCal/AP_AccelCal.cpp

@@ -382,3 +382,9 @@ bool AP_AccelCal::gcs_vehicle_position(float position)
 
     return false;
 }
+
+// true if we are in a calibration process
+bool AP_AccelCal::active(void) const
+{
+    return _status == ACCEL_CAL_WAITING_FOR_ORIENTATION || _status == ACCEL_CAL_COLLECTING_SAMPLE;
+}

libraries/AP_AccelCal/AP_AccelCal.h

@@ -36,6 +36,9 @@ public:
 
     void handleMessage(const mavlink_message_t &msg);
 
+    // true if we are in a calibration process
+    bool active(void) const;
+
 private:
     GCS_MAVLINK *_gcs;
     bool _use_gcs_snoop;