Spektrum sat output on the RX.
quick fix
Fix framesize (only 7 channels), tested with baseflight.
Allow using compilers from system location, if they are not part of Arduino install (e.g. on Fedora)
3.5.2 (spektrum sat output)
Merge branch 'master' into 30-printf

Conflicts:
	RX.h
Merge branch '30-printf' into 35-print-mav

Conflicts:
	RX.h