Make mavlink a config item.
Merge in modified version of mavlink
Merge branch '30-mavlink' into 35-print-mav

Conflicts:
	RX.h
	TX.h
	dialog.h
	hardware.h
	mavlink.h
	openLRSng.ino
Merge branch '35-print-mav' into 40-all

Conflicts:
	RX.h
	TX.h
	binding.h
	dialog.h
Visual inspection of diffs.
Start working on RX packet size.
Split rcv, xmit functions
Debug stage
Make 868/915 firmwares too
Working version.

Still some odd looking data on downlink receive.
Merge branch 'master' into 40-all