Add LLIND functionality. LLIND is binary linkstate output (high when link problems are occurring).
Fix SUMD input
Merge branch 'master' into 19-bcom-in-c
Merge branch '19-bcom-in-c' into 20-standalone

Conflicts:
	RX.h
Merge branch '20-standalone' into 21-bool
Merge branch '21-bool' into 22-printf
Merge branch '22-printf' into 23-wiring
Merge branch '23-wiring' into 24-c-only