* ATC: add transponder system
* I know you want to be but you are not a RMP, ATC
* Update atc.nas
* Update A320-main.xml
* fix
* Disable radios in menubar, change TCAS mode according to transponder switch
* Add new TCAS flags, will be uncommented in 2019.3
* Fix
* Fix
* Hook TCAS to electrical system
* Fix
* Resetting after failure
* Fix
* electrical output now controlled by transponder itself
* Fix
* fix
* fix
* Fix
* Fix
* Bugfixes, add to acconfig
* Re-add radio dialog
* Prevent radio dialog from modifying mode
* Fix clear display
* Remove conflict between dialog and setting the code on the panel
* VC: Cleanup transponder bindings
* Fixes
* Fix
* Fix finally
* Transponder: realign
