Added PPM frame length feedback in IO comms and status command - allows to warn users about badly formatted PPM frames

PPM channel count detection is now using a more paranoid approach.

Custom io scale

Futaba RC failsafe support

this seems to avoid a problem where the mpu6000 doesn't startup
correctly if other devices are transferring at the same time.

Cranking up bus speeds for all sensors to achievable 10.4 MHz

First stab at implementing better RSSI based connection status estimation, still needs some work and testing

This kind of handling might be moved upstream into the application, once alarms are propagated by the ORB system.

This change is compatible with RX failsafe settings, but does not rely on it (uses SBus flags instead).

Device renamed, custom device on parameter switch

update the commander to only use local pos for landing detection when on...