Move NuttX configurations out of the NuttX tree proper. This reduces the diffs we have to carry against the NuttX upstream repo to just our local patches to the NuttX code itself.

ETS airspeed and MEAS airspeed combined driver

Implemented config command, fixed a number range set / get issues for some sensor drivers, fixed gyro calibration

Implemented new, simple system boot config and sane default value system

Hotfix: Ensured there are never two filters running at the same time if auto-magic happens via USB link

Lunchtime HOTFIX: Bring back USB console to operational, allow single-USB connection operation via QGC

Minor cleanup of comments for HoTT messages.