Add testcode behind defines:
  TEST_NO_ACK_BY_CH0 - do not reply from RX in case ch0 > ~1900
  TEST_DUMP_AFCC     - dump AFCC offsets on TX (needs telemetry)
Merge branch 'master' into diversity
Merge branch 'master' into diversity
Merge branch 'master' into diversity
Fix frsky timing
Merge branch 'master' into diversity

Conflicts:
	TX.h
	frskytx.h
Starting with slave stuff...
some initial things...
some bits and pieces...
Merge branch 'master' into diversity
Merge branch 'master' into diversity
Merge branch 'master' into diversity
Merge branch 'master' into diversity
Basic diversity RX code may even work, untested for now.
Merge branch 'master' into diversity
Merge branch 'master' into diversity

Conflicts:
	RX.h
	openLRSng.ino
Merge branch 'master' into 10-Math
Implement slaveRX recovery after failure.
Add libraries folder
v3.5.3 - add diversity support (EXPERIMENTAL)