Add main to project.

Only CPP files are binary_com and the project.
Merge branch '30-printf' into 35-print-mav

Conflicts:
	printf.c
Use only the Serial API for telemetry
Merge branch '30-printf' into 35-print-mav

Conflicts:
	RX.h
	TX.h
More Serial conversion
Merge branch '30-printf' into 35-print-mav
Make mavlink a config item.