message: Add note on "not having a break" (QGC Mission import)
  Added note to indicate that there's no break in the switch case
  between commads MAV_CMD_NAV_WAYPOINT & MAV_CMD_NAV_TAKEOFF. As
  params 4, 5 & 6 of these commands are Lat, Lon & Alt respectively,
  break is omitted. This eliminates redundant code.
diff: @@ -1004,6 +1004,8 @@ MissionImpl::compose_mission_items_from_json(Mission::mission_items_t &mission_i
  break;
  case MAV_CMD_NAV_WAYPOINT:
  is_fly_through = (params[0] == 0.0) ? true : false;
  + // NO break here, because params 4, 5 & 6 of both
  + // of these commands are Lat, Lon & Alt respectively.
  case MAV_CMD_NAV_TAKEOFF:
  lat_deg = params[4];
  lon_deg = params[5];
  