Testing watchdog on RX
Check for optiboot by reading BOOTSZ bits from fuses.
RX: put 'lockup by channel' code inside ifdef HALT_RX_BY_CH2
Fix optiboot detection
Merge branch 'master' into wd
Add WATCHDOG_USED flag to rxconfig.
Bump version to 3.5.6.
TX: watchdog
Merge branch 'wd' of https://github.com/kh4/openLRSng into wd
Fix byteorder for failsafe
Merge branch 'wd' of https://github.com/openLRSng/openLRSng into wd
Fix failsafe editing via configurator
Change WD to 8 seconds
Remove forced delay on failsafe saving.
watchdog refactoring
add debug flags to .ino
Merge branch 'master' into 20-standalone

Conflicts:
	RX.h
Merge branch '20-standalone' into 21-bool
Merge branch '21-bool' into 22-printf

Conflicts:
	RX.h
	TX.h
	binary_com.h
Merge branch '22-printf' into 23-wiring
Merge branch '23-wiring' into 24-c-only