* Use pwrCheck() as primary control point for shutdown, centralizes thread control in simpgmspace module;
* Remove main_thread_running in favor of separate variables for startup mode and shutdown flag;
* Don't start a thread for ARM startup, just run simuMain() directly (the thread just exits anyway);
* Refactor SIMU_SLEEP() macro, and remove all unnecessary uses of it, also remove SIMU_SLEEP_NORET;
* Add startType param to opentxStart() to control splash and startup checks;
* Fixes backlight never turning off in simulator with "SWITCH" power button type (pwrPressed() was always true);
* Fixes simu shutdown when model checklist is displayed at startup;
* Adds stubs to possibly simulate a "soft" power button in the future.
* [X7] S.PORT devices update is now done on the bottom connector
* [X7] I introduce a PCBREV option, as previous versions didn't have this S.PORT bottom connector
* [X7] Introduce a PCBREV PIN to avoid having different 2 different firmware on X7
* Compilation fix
* [X7] PCBREV PIN was inverted
* [X7] PULL DOWN on PCBREV PIN
* S.PORT bottom connector is powered by PB.02, not PB.01
* [X7] PCBREV resistor changed
* [X7] PCBREV resistor changed
* Re #3815: Disk cache: Write statistic added. Bigger disk cache. Show disk cache misses in CLI.
* Update to the latest FatFS R0.12b (all existing OpenTX patches have been already applied in upstream, only few ff.h modifications needed for simulator)
* Missing file
* SD card manager: do not show parent dir [..] for root directory
Bertrand Songis