Beeps and LED blinks cleanup, beep on RC failsafe added

Some cleanup in commander_helper, remember buzzer state in commander_helper to minimize ioctl usage. Added warning beep and amber LED on RC failsafe (the same as low battery).
During testing on FMUv1 + IO I had some suspends (I think stack overflow), after switching from autostart 1001 to 4010 it works, except sdlog2, that exits on arming because of no free memory.

Not tested on FMUv2 yet.