Add clipping information to DrawObj
Add ClippingMgr to geom_core and to Vehicle model
Add Clipping screen to GUI
Add Clipping to OpenGL drawing
Show 'inside' of shaded objects.
Fix infinite recursion in Vehicle::UpdateBBox when no Geom's exist.
Update Code-Eli to include surface skinning support.
Update for changes in create_body_of_revolution
Clean up tabs to spaces in VspSurf
Update to use new Code-Eli skinning for C0, C1, C2 cases.
Use new Code-Eli skinning in Fuselage.
Remove dead spin code.
Add Matrix4d::getBasis to extract basis vectors from transformation matrix.
Add helpers to XSec for building slope/normal vectors from intuitive parameters.
Add rib-based interpolate
Remove un-used typedef for id/piecewise curve pair
Remove modulo 3 continuity skinning test routine.
Change old linear skinning to new style.
Remove un-used legacy skinning routines.
Remove un-used DegreeReduceSections