debugging and cleanup. a couple of open issues:

- would like to save txd/rxd on the v2, so what pin to use for ailR-in? (probably one of the ele/rud sw)
- delta_sw needs to be read via adc first (delta_sw_vr) then translated to delta_sw_vr.
- i think i broke servo out (after rewriting it twice). need to debug it..