Philippe 22/09/2023: sensors: send/recv: allow possibility to not exchange the sensor data (reduce communications)

Philippe 17/05/2023: sensors: add deallocation subroutines + small improvements for allocation subroutines

Philippe 26/04/2023: flyers: rename CTITLE in CNAME (for future partial merge with stations and profilers)

Philippe 18/01/2023: balloons: write position in backup files for current and all ancestry models (at correct instant)

Useful to allow transfer of flyers between processses (to be developed)

Philippe 02/06/2022: flyers: put all aircrafts in TAIRCRAFTS and balloons in TBALLOONS (array instead of separated variables)

Warning: not tested