params: fix default yaw tuning, improve stab rate
flight.control.position partially plumbed & stubbed out
flight: refactor GCS to take datatypes rather than billion args

smaccmpilot, now with 47% less code smell!
wibble
flight.control.position implemented in terms of StatePID

* StatePID can be used to replace a couple of other controllers
  too! and maybe we can even generalize/parameterize it a little bit to replace
  Control.PID completely!
* except that its all completely untested
update hil params
apwrapper sensors capture: give compass gps for declination
flight.control: input and output datastructures
flight.control.position: morally complete zero-velocity ctl, but no law yet
commented out for pat so a runtime assertion isn't hit (will fix the bug soon).