Use WingCentroid() instead of AerodynamicCenter in shielding calculations.
AerodynamicCenter is usually zero (not calculated yet) when shielding is calculated, and anyway, it's shifted by dynamic variables like velocity and AoA, not good for shielding, WingCentroid() is more geometric (static).
Fixed newly attached procedural fairings being shielded by their base:
Update fairing aerodynamic parameters when the shape is changed, update shielding in editor too.
Merge pull request #7 from e-dog/master

Sounds good.  In it goes.