Minor bug fixes and improvements

Changes made for macOS 26 Tahoe.

This version requires as least macOS 11.5 Big Sur. A lot of internal house keeping was made and deprecated system routines were removed.
New: A tcp/ip connection is supported now to all horizontal rotors.

* Fix: Better satellite footprints over the poles
* New: Added options to select the number of orbits for the satellite path preview
* New: Added column in the satellite data table to show the orbit period

* TLE download links to celestrak.org updated
* TLE download from amsat.org added
* Improved doppler correction
* Support for Sky-Watcher Adventurer GTi added

Since the Green Heron RT-21 Azimuth controller has a (W)LAN option, a network control option for this controller was added.

Improvements made for the GS232A and GS232B protocol with elevation control.

Fix: Uncommanded movement to 208º when using a Alfa ROT1Prog Controller - Tnx Georg, DJ6GI
New: Rotor control debug information, useful to troubleshoot control issues: Menu-->Window-->Rotor Debug Window

New: Added rows in the SAT table for max. elevation and doppler shift for 21 MHz.
New: Added a second transceiver option to use different devices for up- and downlink.
New: Added a Note field for each SAT preset. See Preferences-->Satellites-->Note. You can enter a free text note. The note will be presented when you select a SAT in the trx tracking section. It's useful to review the band plan or other stuff to remember.

Added a column for max. elevation in the satellite table

Fixed a problem saving few settings in the Preferences
User editable callsign-grid square database added. Useful for VHF/UHF contests, see the Help file.

User editable callsign-grid square database added. Useful for VHF/UHF contests, see the Help file.

Failure in a direction calculation (to a grid square) corrected - Tnx Dana, VE3DS

Fixed a problem when using a 32u4 based Arduino for the SARCNET controller - Tnx Klaus, 9V1KG

* Support for Prosistel  controllers (azimuth and elevation) - Tnx Andrea, IU3MIK
* Elevation support for the GS-232A and GS-232B protocols, tested with the ERC-M controller - Tnx Frank, DH4FR / PA4FR

Green Heron RT-21 (DCU-1) controller added - Tnx Dana, VE3DS

* Preferences window restructured
* New option for bidirectional antennas added
* New option for offset mounted antennas added