Plane: log to dataflash statustext messages from my_gcs

ArduPlane/GCS_Mavlink.cpp

@@ -1150,6 +1150,20 @@ void GCS_MAVLINK_Plane::handleMessage(mavlink_message_t* msg)
         break;
     }
 
+    case MAVLINK_MSG_ID_STATUSTEXT:
+    {
+        // ignore any statustext messages not from our GCS:
+        if (msg->sysid != plane.g.sysid_my_gcs) {
+            break;
+        }
+        mavlink_statustext_t packet;
+        mavlink_msg_statustext_decode(msg, &packet);
+        char text[MAVLINK_MSG_STATUSTEXT_FIELD_TEXT_LEN+1+4] = { 'G','C','S',':'};
+        memcpy(&text[4], packet.text, MAVLINK_MSG_STATUSTEXT_FIELD_TEXT_LEN);
+        plane.DataFlash.Log_Write_Message(text);
+        break;
+    }
+
     case MAVLINK_MSG_ID_COMMAND_INT:
     {
         // decode