Continued cleaning of e407_serial
Retabbed e407-serial
Moved debug test from servo_control to host_fc/servo_test
Merged servo_control and psas_packet into main.c

It's very ugly right now, I didn't do any attept at cleanup. That's
coming later.
Moved BQ3060 fault register readers to the timer callback
Changed PWM timer from VT to event driven

This means we no longer need to stay with I-Class functions in set_pwm_position
Moved error socket write to pwn callback
Made pwm checks driven by pwm period
Retabbed flight-servo
Added proper error returns to flight-servo
Added preprocessor conditional to turn off dev checks in flight-servo
Added RCI Version command to flight-servo