Comment cleanup
CJMCU - Update PPM/PWM mappings.

Bench tested for PPM & 4 Motor outputs only.
CJMCU - Use 64k/128k flash specific linker scripts scripts
Fix PWM failsafe by monitoring for missing pwm rise/fall signal events.
Reduce code size and ram usage of PWM supervisor code.
Delete unused code.
Removing cruft from makefile that was accidentally committed when
working on the CJMCU target.
Merge branch 'master' into msp-on-multiple-ports